KT Scientific Publications

@article{Lew-Yee2026b,

title = {A Python-Based Module for Exploring Machine Learning-Inspired Optimization Algorithms Using Quantum Chemistry},

author = {Juan Felipe Huan Lew-Yee and Elixabete Rezabal and Xabier Lopez and Mario Piris and Jose M. Mercero},

doi = {10.1021/acs.jchemed.5c01470},

issn = {1938-1328},

year  = {2026},

date = {2026-07-14},

urldate = {2026-07-14},

journal = {J. Chem. Educ.},

volume = {103},

number = {7},

pages = {3929--3937},

publisher = {American Chemical Society (ACS)},

keywords = {IT2067, MatCat-KT, NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {5- and 6-Membered Rings: A Natural Orbital Functional Study},

author = {Ion Mitxelena and Juan Felipe Huan Lew-Yee and Mario Piris},

doi = {https://doi.org/10.1021/acs.jctc.5c01861},

year  = {2026},

date = {2026-03-05},

urldate = {2026-03-05},

journal = {Journal of Chemical Theory and Computation},

volume = {22},

issue = {6},

pages = {2799-2807},

abstract = {The Global Natural Orbital Functional (GNOF) provides a straightforward approach to capture most electron correlation effects without needing perturbative corrections or limited active spaces selection. In this work, we evaluate both the original GNOF and its modified variant, GNOFm, on a set of twelve 5- and 6-membered molecular rings, systems characterized primarily by dynamic correlation. This reference set is vital as it comprises essential substructures of more complex molecules. We report complete-basis-set limit correlation energies for GNOF, GNOFm, and the benchmark CCSD(T) method. Across the Dunning basis sets, both functionals deliver a balanced and accurate description of the molecular set, with GNOFm showing small but systematic improvements while preserving the overall robustness of the original formulation. These results confirm the reliability of the GNOF family and its ability to capture dynamic correlation effects.},

keywords = {IT2067, NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Lew-Yee2026,

title = {DoNOF 2.0: A modern open-source electronic structure program for natural orbital functionals},

author = {Juan Felipe Huan Lew-Yee and Ion Mitxelena and Jorge M. del Campo and Mario Piris},

doi = {10.1063/5.0316927},

issn = {1089-7690},

year  = {2026},

date = {2026-02-18},

urldate = {2026-02-18},

journal = {The Journal of Chemical Physics},

volume = {164},

issue = {7},

pages = {072501},

publisher = {AIP Publishing},

abstract = {In this work, we present the second version of the Donostia natural orbital functional software, an open-source program for natural orbital functional calculations. The new release incorporates improved optimization algorithms, capabilities for excited-state computations, support for ab initio molecular dynamics, and integration with the libcint library. DoNOF 2.0 also extends its property toolbox by enabling the evaluation of nonlinear optical responses, including static polarizabilities and higher-order hyperpolarizabilities via a finite-field Romberg–Richardson scheme.},

keywords = {IT2067, NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Lew-Yee_Piris_2025,

title = {Metal-Insulator Transition described by NOFT},

author = {Juan Felipe Huan Lew-Yee and Mario Piris },

url = {https://www.revistacubanadefisica.org/index.php/rcf/article/view/53},

issn = {e-ISSN 2224-7939, p-ISSN 0253-9268},

year  = {2025},

date = {2025-07-15},

urldate = {2025-07-15},

journal = {Revista Cubana de Física},

volume = {42},

number = {1},

pages = {30-36},

abstract = {The metal–insulator transition (MIT) is a fundamental phenomenon in condensed matter physics and a hallmark of strong electronic correlations. Hydrogen-based systems offer a simple yet powerful model for investigating the MIT, as their insulating behavior arises purely from electron–electron interactions. In this work, we study finite hydrogen clusters with cubic geometries using Natural Orbital Functional Theory (NOFT), a method capable of accurately describing correlated systems beyond mean-field approaches. We focus on two key signatures of the MIT: the fundamental energy gap and the harmonic average of the atomic one-particle reduced density matrix. Our results show that NOFT captures the transition from insulating to metallic behavior as the interatomic distance decreases. By extrapolating the energy gap to the thermodynamic limit, we estimate a critical distance rc ~1.2 Å, in excellent agreement with quantum Monte Carlo benchmarks. These findings demonstrate the reliability of NOFT for describing strong correlation effects in large-scale models.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Lew-Yee2025b,

title = {Advancing Natural Orbital Functional Calculations through Deep Learning-Inspired Techniques for Large-Scale Strongly Correlated Electron Systems},

author = {Juan Felipe Huan Lew-Yee and Jorge M. del Campo and Mario Piris},

doi = {10.1103/physrevlett.134.206401},

issn = {1079-7114},

year  = {2025},

date = {2025-05-20},

urldate = {2025-05-20},

journal = {Phys. Rev. Lett.},

volume = {134},

pages = {206401},

publisher = {American Physical Society (APS)},

abstract = {Natural orbital functional (NOF) theory provides a valuable framework for studying strongly correlated systems at an affordable computational cost, with an accuracy comparable to highly demanding wave-function-based methods. However, its widespread adoption in cases involving a large number of correlated electrons has been limited by the extensive iterations required for convergence. In this Letter, we present an approach that integrates the techniques used for optimization in deep learning into NOF calculations, enabling a substantial expansion in the scale of accessible systems. The proposed procedure employs an adaptive momentum-based technique for orbital optimization, alternated with the optimization of occupation numbers, significantly improving the computational feasibility of challenging calculations. We illustrate the capabilities of our approach through three challenging test cases: (i) the symmetric dissociation of a large hydrogen cluster with 1000 electrons, (ii) an analysis of occupancy distributions in fullerenes, and (iii) a study of the singlet-triplet energy gap in linear acenes. These examples demonstrate the method’s applicability to large-scale systems and strongly correlated electron phenomena, extending the reach of NOF theory to increasingly complex systems.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Lew-Yee2025,

title = {Efficient Energy Measurement of Chemical Systems via One-Particle Reduced Density Matrix: A NOF-VQE Approach for Optimized Sampling},

author = {Juan Felipe Huan Lew-Yee and Mario Piris},

doi = {10.1021/acs.jctc.4c01734},

issn = {1549-9626},

year  = {2025},

date = {2025-03-11},

urldate = {2025-03-11},

journal = {J. Chem. Theory Comput.},

volume = {21},

issue = {5},

pages = {2402-2413},

publisher = {American Chemical Society (ACS)},

abstract = {In this work, we explore the use of the one-particle reduced density matrix (1RDM) to streamline energy measurements of chemical systems on quantum computers, particularly within the variational quantum eigensolver (VQE) framework. This approach leverages the existence of an exact energy functional of the 1RDM, enabling a reduction in both the number of expectation values to measure and the number of circuits to execute, thereby optimizing quantum resource usage. Specifically, sampling the 1RDM involves measuring only  elements, which is significantly fewer than the  required for the Hamiltonian’s expectation value ⟨Ĥ⟩. We demonstrate our approach by harnessing the well-established natural orbital functional (NOF) theory, using the natural orbitals and occupation numbers derived from the diagonalization of the 1RDM measured from the quantum computer. Starting with the H2 system, we validate the accuracy of our method by comparing the energy derived from NOF approximations applied to the exact wave function with the value obtained from ⟨Ĥ⟩. This is followed by an optimization of the gate parameters by minimizing the energy using the NOF approximations as the objective function. The analysis is extended to larger systems, such as LiH, Li2, OH–, FH, NeH+, and F2 using a wave function ansatz with single and double excitation gates. This NOF-based method reduces the scaling cost of circuit executions compared to standard VQE implementations, achieving around 90% savings in the systems used in this work. Overall, by using a well-performing NOF as the objective function, the proposed NOF-VQE demonstrates the viability of NOF approximations for obtaining accurate energies in the noisy intermediate-scale quantum era and underscores the potential for developing new functionals tailored to quantum computing applications.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{2025,

title = {Enhancing the computational efficiency of the DoNOF program through a new orbital sorting scheme},

author = {Élodie Boutou and Juan Felipe Huan Lew-Yee and Jose M. Mercero and Mario Piris},

doi = {10.1016/bs.aiq.2025.03.001},

isbn = {9780443343575},

year  = {2025},

date = {2025-02-04},

urldate = {2025-02-04},

booktitle = {Advances in Quantum Chemistry},

journal = {Advances in Quantum Chemistry},

volume = {91},

pages = {169--189},

publisher = {Elsevier},

abstract = {This work presents a novel approach to distribute orbitals into subspaces within electron-pairing-based natural orbital functionals (NOFs). This approach modifies the coupling between weakly and strongly occupied orbitals by applying an alternating orbital sorting strategy. In contrast to the previous orbital sorting that enforced electron pairing within subspaces of contiguous orbitals, the new approach provides greater flexibility, enabling a calculation scheme where the size of the subspaces can be gradually expanded. As a consequence, one can start using subspaces of only one weakly occupied orbital (perfect pairing) and progressively enlarge their size by incorporating more weakly occupied orbitals (extended pairing) up to the maximum size allowed by the basis set. In this way, the alternate orbital sorting allows solving first a simpler problem with small subspaces and leverage its orbital solution for the more intensive problem with larger subspaces, thereby reducing the overall computational cost and improving convergence, as we observed in the DoNOF program. The efficiency provided by the new sorting approach has been validated through benchmark calculations in H2O, H2O2, and NH3. In particular, we compared three strategies: (i) solving directly the calculation with the largest subspaces (one-shot strategy), as was usually done before this work, (ii) starting with perfect pairing and stepwise increasing the number of orbitals in the subspaces one by one until reaching the maximum size (incremental strategy), and (iii) starting with perfect pairing and transitioning directly to the maximum subspace size (two-step strategy). Our results show that the two-step approach emerges as the most effective strategy, achieving the lowest computational cost while maintaining high accuracy. These results confirm that the alternating orbital sorting scheme provides a robust and scalable framework for improving NOF calculations and could be particularly advantageous for extending these methods to larger and strongly correlated systems.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Piris2024b,

title = {Time-Resolved Chemical Bonding Structure Evolution by Direct-Dynamics Chemical Simulations},

author = {Mario Piris and Xabier Lopez and Jesus M. Ugalde},

doi = {10.1021/acs.jpclett.4c03010},

issn = {1948-7185},

year  = {2024},

date = {2024-11-28},

urldate = {2024-11-28},

journal = {J. Phys. Chem. Lett.},

volume = {15},

issue = {49},

pages = {12138-12143},

publisher = {American Chemical Society (ACS)},

abstract = {Direct-dynamics simulations monitor atomic nuclei trajectories during chemical reactions, where chemical bonds are broken and new ones are formed. While they provide valuable information about the ongoing nuclear dynamics, the evolution of the chemical bonds is customarily overlooked, thus, hindering key information about the reaction mechanism. Here we examine the evolution of the chemical bonds for the three main mechanisms of the F– + CH3CH2Cl reaction using quasi-classical trajectories for the nuclei, and global natural orbitals for the electrons. Key findings include (i) bimolecular nucleophilic substitution (SN2) resembles a one-step bond breaking and formation process; (ii) the elimination mechanisms (syn- and anti-E2) feature a sequential two-step process of proton abstraction and Cl– elimination; and (iii) the anti-E2 mechanism is slower, exhibits rebound effects, and gets activated by specific vibrational modes. This study highlights the importance of correctly describing and thoroughly analyzing the dynamical evolution of chemical bonds for chemical reaction mechanistic studies.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Piris2024,

title = {Exploring the potential of natural orbital functionals},

author = {Mario Piris},

doi = {10.1039/d4sc05810k},

issn = {2041-6539},

year  = {2024},

date = {2024-10-30},

urldate = {2024-10-30},

journal = {Chem. Sci.},

volume = {15},

number = {42},

pages = {17284--17291},

publisher = {Royal Society of Chemistry (RSC)},

abstract = {<jats:p>In recent years, Natural Orbital Functional (NOF) theory has gained importance in quantum chemistry, effectively addressing a major challenge: providing accurate and balanced descriptions of systems with strong electronic correlation.</jats:p>},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Piris2024c,

title = {Advances in approximate natural orbital functionals: From historical perspectives to contemporary developments},

author = {Mario Piris},

editor = {Ramon A. Miranda Quintana, John F. Stanton},

doi = {10.1016/bs.aiq.2024.04.002},

isbn = {9780443237980},

year  = {2024},

date = {2024-08-31},

urldate = {2024-08-31},

booktitle = {Advances in Quantum Chemistry},

journal = {Advances in Quantum Chemistry},

volume = {90},

pages = {15-66},

publisher = {Elsevier},

series = {Advances in Quantum Chemistry},

abstract = {This chapter provides a comprehensive review of fundamental concepts related to approximate natural orbital functionals (NOFs), emphasizing their significance in quantum chemistry and physics. Focusing on fermions, the discussion excludes considerations of finite temperature and systems with a variable number of particles. The theoretical foundation for approximate NOFs is laid out, with a particular emphasis on functional N-representability. Various two-index reconstructions for the two-particle reduced density matrix are introduced, accompanied by discussions on challenges. The analysis delves deeply into NOFs grounded in electron pairing, specifically focusing on PNOF5, PNOF7, and the Global NOF, a more versatile approach addressing both static and dynamic electron correlation components. The extension of NOFs to multiplets while conserving total spin is presented, and the availability of open-source implementations like DoNOF and its associated programs is highlighted. A detailed overview of optimization procedures for single-point calculations is provided. Sections on geometry optimization and ab initio molecular dynamics, closely connected to the availability of analytical gradients in NOF theory, are presented. The chapter concludes with the extension of NOFs to both charged and excited states.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Franco2024,

title = {Softmax parameterization of the occupation numbers for natural orbital functionals based on electron pairing approaches},

author = {Lizeth Franco and Iván A. Bonfil-Rivera and Juan Felipe Huan Lew-Yee and Mario Piris and Jorge M. del Campo and Rodrigo A. Vargas-Hernández},

doi = {10.1063/5.0213719},

issn = {1089-7690},

year  = {2024},

date = {2024-06-28},

urldate = {2024-06-28},

journal = {J. Chem. Phys.},

volume = {160},

number = {24},

pages = {244107},

publisher = {AIP Publishing},

abstract = {<jats:p>Within the framework of natural orbital functional theory, having a convenient representation of the occupation numbers and orbitals becomes critical for the computational performance of the calculations. Recognizing this, we propose an innovative parametrization of the occupation numbers that takes advantage of the electron-pairing approach used in Piris natural orbital functionals through the adoption of the softmax function, a pivotal component in modern deep-learning models. Our approach not only ensures adherence to the N-representability of the first-order reduced density matrix (1RDM) but also significantly enhances the computational efficiency of 1RDM functional theory calculations. The effectiveness of this alternative parameterization approach was assessed using the W4-17-MR molecular set, which demonstrated faster and more robust convergence compared to previous implementations.</jats:p>},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Mitxelena2024,

title = {Assessing the global natural orbital functional approximation on model systems with strong correlation},

author = {Ion Mitxelena and Mario Piris},

doi = {10.1063/5.0207325},

issn = {1089-7690},

year  = {2024},

date = {2024-05-28},

urldate = {2024-05-28},

journal = {J. Chem. Phys.},

volume = {160},

number = {20},

pages = {204106},

publisher = {AIP Publishing},

abstract = {<jats:p>In the past decade, natural orbital functional (NOF) approximations have emerged as prominent tools for characterizing electron correlation. Despite their effectiveness, these approaches, which rely on natural orbitals and their associated occupation numbers, often require hybridization with other methods to fully account for all correlation effects. Recently, a global NOF (GNOF) has been proposed [Piris, Phys. Rev. Lett. 127, 233001 (2021)] to comprehensively address both dynamic and static correlations. This study evaluates the performance of GNOF on strongly correlated model systems, including comparisons with highly accurate Full Configuration Interaction calculations for hydrogen atom clusters in one, two, and three dimensions. Additionally, the investigation extends to a BeH2 reaction, involving the insertion of a beryllium atom into a hydrogen molecule along a C2v pathway. According to the results obtained using GNOF, consistent behavior is observed across various correlation regions, encompassing a range of occupations and orbital schemes. Furthermore, distinctive features are identified when varying the dimensionality of the system.</jats:p>},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Lew-Yee2024,

title = {Excited States by Coupling Piris Natural Orbital Functionals with the Extended Random-Phase Approximation},

author = {Juan Felipe Huan Lew-Yee and Iván Alejandro Bonfil-Rivera and Mario Piris and Jorge M. del Campo},

doi = {10.1021/acs.jctc.3c01194},

issn = {1549-9626},

year  = {2024},

date = {2024-03-12},

urldate = {2024-03-12},

journal = {J. Chem. Theory Comput.},

volume = {20},

issue = {5},

pages = {2140-2151},

publisher = {American Chemical Society (ACS)},

abstract = {In this work, we explore the use of Piris natural orbital functionals (PNOFs) to calculate excited-state energies by coupling their reconstructed second-order reduced density matrix with the extended random-phase approximation (ERPA). We have named the general method PNOF-ERPA, and specific approaches are referred to as PNOF-ERPA0, PNOF-ERPA1, and PNOF-ERPA2, according to the way the excitation operator is built. The implementation has been tested in the first excited states of H2, HeH+, LiH, Li2, and N2 showing good results compared to the configuration interaction (CI) method. As expected, an increase in accuracy is observed on going from ERPA0 to ERPA1 and ERPA2. We also studied the effect of electron correlation included by PNOF5, PNOF7, and the recently proposed global NOF (GNOF) on the predicted excited states. PNOF5 appears to be good and may even provide better results in very small systems, but including more electron correlation becomes important as the system size increases, where GNOF achieves better results. Overall, the extension of PNOF to excited states has been successful, making it a promising method for further applications.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RiveroSantamaría2024,

title = {Time evolution of natural orbitals in \textit{ab initio} molecular dynamics},

author = {Alejandro Rivero-Santamaría and Mario Piris},

doi = {10.1063/5.0188491},

issn = {1089-7690},

year  = {2024},

date = {2024-02-21},

urldate = {2024-02-21},

journal = {J. Chem. Phys.},

volume = {160},

number = {7},

pages = { 071102 },

publisher = {AIP Publishing},

abstract = {<jats:p>This work combines for the first time ab initio molecular dynamics (AIMD) within the Born–Oppenheimer approximation with a global natural orbital functional (GNOF), an approximate functional of the one-particle reduced density matrix. The most prominent feature of GNOF-AIMD is its ability to display the real-time evolution of natural orbitals, providing detailed information on the time-dependent electronic structure of complex systems and processes, including reactive collisions. The quartet ground-state reaction N(4S) + H2(1Σ) → NH(3Σ) + H(2S) is taken as a validation test. Collision energy influences on integral cross sections for different initial rovibrational states of H2 and rotational-state distributions of the NH product are discussed, showing a good agreement with previous high-quality theoretical results.</jats:p>},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Mercero2023,

title = {Natural orbital functional theory studies of all-metal aromaticity: The Al3 anion},

author = {Jose M. Mercero and Rafael Grande-Aztatzi and Jesus M. Ugalde and Mario Piris},

doi = {10.1016/bs.aiq.2023.02.006},

isbn = {9780443186639},

year  = {2023},

date = {2023-10-01},

urldate = {2023-10-01},

booktitle = {Advances in Quantum Chemistry},

journal = {Adv. Quantum Chem.},

volume = {88},

pages = {229-248},

publisher = {Elsevier},

series = {Advances in Quantum Chemistry},

abstract = {In this chapter, the Al3− triangle singlet, triplet, and quintet states have been characterized. This study is developed from the point of view of an approximate natural orbital functional (NOF), for which the energy of the ground state is given as a functional of the natural orbitals and their occupation numbers. Specifically, the recently proposed global NOF (Piris, 2021 in Ref. 22) is used to address the electron delocalization features of an all-metal aromatic compound, the Al

 ring-like cluster anion in its lowest-lying electronic states of different spin. Its aromaticity is characterized by the multicenter index (MCI) and its π-fraction (MCIπ) by comparing them with paradigmatic cases of aromatic and antiaromatic organic compounds, namely benzene and cyclobutadiene. Our results have been compared with the highly accurate multiconfigurational self-consistent field (MCSCF) method complemented with quasidegenerate perturbation theory (MCQDPT) perturbative corrections, and with the available experimental data. GNOF was found to be able to give a satisfactorily quantitative agreement with the MCSCF/MCQDPT results and experiment, and also describing both the π- and σ-aromaticity of the 

, and the 3B2 states.},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{Lew-Yee2022,

title = {Electron Correlation in the Iron(II) Porphyrin by Natural Orbital Functional Approximations},

author = {Juan Felipe Huan Lew-Yee and Jorge M. del Campo and Mario Piris},

doi = {10.1021/acs.jctc.2c01093},

issn = {1549-9626},

year  = {2023},

date = {2023-01-10},

urldate = {2023-01-10},

journal = {J. Chem. Theory Comput.},

volume = {19},

number = {1},

pages = {211--220},

publisher = {American Chemical Society (ACS)},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN284,

title = {Outstanding improvement in removing the delocalization error by global natural orbital functional},

author = {J. F. H. Lew-Yee and M. Piris and J. M. Campo},

url = {<Go to ISI>://WOS:000939773200005},

doi = {10.1063/5.0137378},

issn = {0021-9606},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Journal of Chemical Physics},

volume = {158},

number = {8},

pages = {084110},

note = {Lew-Yee, Juan Felipe Huan Piris, Mario del Campo, Jorge M. 

Piris, Mario/E-7406-2010; Martin del Campo, Jorge/J-3716-2014 

Piris, Mario/0000-0003-0222-2953; Lew-Yee, Juan Felipe Huan/0000-0002-3908-3144; Martin del Campo, Jorge/0000-0002-4195-3487 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN285,

title = {Electron Correlation in the Iron(II) Porphyrin by Natural Orbital Functional Approximations},

author = {J. F. H. Lew-Yee and J. M. Campo and M. Piris},

url = {<Go to ISI>://WOS:000914945300001},

doi = {10.1021/acs.jctc.2c01093},

issn = {1549-9618},

year  = {2022},

date = {2022-12-29},

urldate = {2022-12-29},

journal = {Journal of Chemical Theory and Computation},

volume = {19},

issue = {1},

pages = {211–220},

note = {Lew-Yee, Juan Felipe Huan del Campo, Jorge M. Piris, Mario 

Piris, Mario/E-7406-2010; Martin del Campo, Jorge/J-3716-2014 

Piris, Mario/0000-0003-0222-2953; Martin del Campo, Jorge/0000-0002-4195-3487; Lew-Yee, Juan Felipe Huan/0000-0002-3908-3144 

1549-9626},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN286,

title = {Benchmarking GNOF against FCI in challenging systems in one, two, and three dimensions},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000830421800007},

doi = {10.1063/5.0092611},

issn = {0021-9606},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Journal of Chemical Physics},

volume = {156},

number = {21},

pages = { 214102},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN290,

title = {DoNOF: An open-source implementation of natural-orbital-functional-based methods for quantum chemistry},

author = {M. Piris and I. Mitxelena},

url = {<Go to ISI>://WOS:000599925900002},

doi = {10.1016/j.cpc.2020.107651},

issn = {0010-4655},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Computer Physics Communications},

volume = {259},

note = {Piris, Mario Mitxelena, Ion 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1879-2944},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN8,

title = {Chemical reactivity studies by the natural orbital functional second-order Moller-Plesset (NOF-MP2) method: water dehydrogenation by the scandium cation},

author = {J. M. Mercero and J. M. Ugalde and M. Piris},

url = {<Go to ISI>://WOS:000656459800001},

doi = {10.1007/s00214-021-02775-4},

issn = {1432-881X},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Theoretical Chemistry Accounts},

volume = {140},

number = {6},

note = {Mercero, Jose M. Ugalde, Jesus M. Piris, Mario 

Ugalde, Jesus/M-2771-2014; Piris, Mario/E-7406-2010; Mercero, Jose/E-6828-2010 

Ugalde, Jesus/0000-0001-8980-9751; Piris, Mario/0000-0003-0222-2953; Mercero, Jose/0000-0003-4857-6685 

1432-2234},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN291,

title = {Spectroscopic properties of open shell diatomic molecules using Piris natural orbital functionals},

author = {R. Quintero-Monsebaiz and L. I. Perea-Ramirez and M. Piris and A. Vela},

url = {<Go to ISI>://WOS:000614634000045},

doi = {10.1039/d0cp05430e},

issn = {1463-9076},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Physical Chemistry Chemical Physics},

volume = {23},

number = {4},

pages = {2953-2963},

note = {Quintero-Monsebaiz, Raul Perea-Ramirez, Luis Ignacio Piris, Mario Vela, Alberto 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; Perea-Ramirez, Luis Ignacio/0000-0002-0736-0936; Vela, Alberto/0000-0002-2794-8622 

1463-9084},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN288,

title = {Global Natural Orbital Functional: Towards the Complete Description of the Electron Correlation},

author = {M. Piris},

url = {<Go to ISI>://WOS:000728930500007},

doi = {10.1103/PhysRevLett.127.233001},

issn = {0031-9007},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Physical Review Letters},

volume = {127},

number = {23},

note = {Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1079-7114},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN287,

title = {Coupling Natural Orbital Functional Theory and Many-Body Perturbation Theory by Using Nondynamically Correlated Canonical Orbitals},

author = {M. Rodriguez-Mayorga and I. Mitxelena and F. Bruneval and M. Piris},

url = {<Go to ISI>://WOS:000752980200020},

doi = {10.1021/acs.jctc.1c00858},

issn = {1549-9618},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Journal of Chemical Theory and Computation},

volume = {17},

number = {12},

pages = {7562-7574},

note = {Rodriguez-Mayorga, Mauricio Mitxelena, Ion Bruneval, Fabien Piris, Mario 

Bruneval, Fabien/C-6923-2009; Rodriguez Mayorga, Mauricio/AHB-2658-2022; Piris, Mario/E-7406-2010 

Bruneval, Fabien/0000-0003-0885-8960; Rodriguez Mayorga, Mauricio/0000-0003-0869-9787; Piris, Mario/0000-0003-0222-2953 

1549-9626},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN289,

title = {Resolution of the identity approximation applied to PNOF correlation calculations},

author = {J. F. H. Lew-Yee and M. Piris and J. M. Campo},

url = {<Go to ISI>://WOS:000630519800001},

doi = {10.1063/5.0036404},

issn = {0021-9606},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Journal of Chemical Physics},

volume = {154},

number = {6},

note = {Huan Lew-Yee, Juan Felipe Piris, Mario del Campo, Jorge M. 

del Campo, Jorge M./J-3716-2014; Piris, Mario/E-7406-2010 

del Campo, Jorge M./0000-0002-4195-3487; Piris, Mario/0000-0003-0222-2953; Lew-Yee, Juan Felipe Huan/0000-0002-3908-3144 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN294,

title = {An efficient method for strongly correlated electrons in two-dimensions},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000522040400011},

doi = {10.1063/1.5140985},

issn = {0021-9606},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {Journal of Chemical Physics},

volume = {152},

number = {6},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN292,

title = {Analytic gradients for spin multiplets in natural orbital functional theory},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000555103900001},

doi = {10.1063/5.0012897},

issn = {0021-9606},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {Journal of Chemical Physics},

volume = {153},

number = {4},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN293,

title = {An efficient method for strongly correlated electrons in one dimension},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000520456800001},

doi = {10.1088/1361-648X/ab6d11},

issn = {0953-8984},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {Journal of Physics-Condensed Matter},

volume = {32},

number = {17},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1361-648x},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN296,

title = {Performance of the NOF-MP2 method in hydrogen abstraction reactions},

author = {X. Lopez and M. Piris},

url = {<Go to ISI>://WOS:000471069400001},

doi = {10.1007/s00214-019-2475-5},

issn = {1432-881X},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

journal = {Theoretical Chemistry Accounts},

volume = {138},

number = {7},

note = {Lopez, Xabier Piris, Mario 

Piris, Mario/E-7406-2010; Lopez, Xabier/G-5690-2015 

Piris, Mario/0000-0003-0222-2953; Lopez, Xabier/0000-0002-2711-3588 

1432-2234},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN295,

title = {Natural orbital functional for multiplets},

author = {M. Piris},

url = {<Go to ISI>://WOS:000485187700006},

doi = {10.1103/PhysRevA.100.032508},

issn = {2469-9926},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

journal = {Physical Review A},

volume = {100},

number = {3},

note = {Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

2469-9934},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN298,

title = {Natural orbital functional for spin-polarized periodic systems},

author = {R. Quintero-Monsebaiz and I. Mitxelena and M. Rodriguez-Mayorga and A. Vela and M. Piris},

url = {<Go to ISI>://WOS:000459439200001},

doi = {10.1088/1361-648X/ab0170},

issn = {0953-8984},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

journal = {Journal of Physics-Condensed Matter},

volume = {31},

number = {16},

note = {Quintero-Monsebaiz, Raul Mitxelena, Ion Rodriguez-Mayorga, Mauricio Vela, Alberto Piris, Mario 

Piris, Mario/E-7406-2010; Rodriguez Mayorga, Mauricio/AHB-2658-2022 

Piris, Mario/0000-0003-0222-2953; Rodriguez Mayorga, Mauricio/0000-0003-0869-9787; MITXELENA, ION/0000-0003-1064-5139 

1361-648x},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN303,

title = {Analytic second-order energy derivatives in natural orbital functional theory},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000428816800010},

doi = {10.1007/s10910-018-0870-0},

issn = {0259-9791},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {Journal of Mathematical Chemistry},

volume = {56},

number = {5},

pages = {1445-1455},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1572-8897},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN301,

title = {Dynamic electron-correlation energy in the natural-orbital-functional second-order-Moller-Plesset method from the orbital-invariant perturbation theory},

author = {M. Piris},

url = {<Go to ISI>://WOS:000441330400005},

doi = {10.1103/PhysRevA.98.022504},

issn = {2469-9926},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {Physical Review A},

volume = {98},

number = {2},

note = {Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

2469-9934},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN304,

title = {NOF-MP2: Global method for electron correlation},

author = {M. Piris},

url = {<Go to ISI>://WOS:000435537706574},

issn = {0065-7727},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {Abstracts of Papers of the American Chemical Society},

volume = {255},

note = {Piris, Mario 

255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water 

Mar 18-22, 2018 

New Orleans, LA 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN305,

title = {On the performance of natural orbital functional approximations in the Hubbard model (vol 29, 425602, 2017)},

author = {I. Mitxelena and M. Piris and M. Rodriguez-Mayorga},

url = {<Go to ISI>://WOS:000423841700001},

doi = {10.1088/1361-648X/aaa659},

issn = {0953-8984},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {Journal of Physics-Condensed Matter},

volume = {30},

number = {8},

note = {Mitxelena, Ion Piris, Mario Rodriguez-Mayorga, Mauricio 

Piris, Mario/E-7406-2010; Rodriguez Mayorga, Mauricio/AHB-2658-2022 

Piris, Mario/0000-0003-0222-2953; Rodriguez Mayorga, Mauricio/0000-0003-0869-9787 

1361-648x},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN302,

title = {Phase dilemma in natural orbital functional theory from the N-representability perspective},

author = {I. Mitxelena and M. Rodriguez-Mayorga and M. Piris},

url = {<Go to ISI>://WOS:000435524200004},

doi = {10.1140/epjb/e2018-90078-8},

issn = {1434-6028},

year  = {2018},

date = {2018-01-01},

urldate = {2018-01-01},

journal = {European Physical Journal B},

volume = {91},

number = {6},

note = {Mitxelena, Ion Rodriguez-Mayorga, Mauricio Piris, Mario 

Rodriguez Mayorga, Mauricio/AHB-2658-2022; Piris, Mario/E-7406-2010 

Rodriguez Mayorga, Mauricio/0000-0003-0869-9787; Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1434-6036},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{WOS:000410585900049,

title = {Comprehensive benchmarking of density matrix functional approximations},

author = {Mauricio Rodriguez-Mayorga and Eloy Ramos-Cordoba and Mireia Via-Nadal and Mario Piris and Eduard Matito},

doi = {10.1039/c7cp03349d},

issn = {1463-9076},

year  = {2017},

date = {2017-09-01},

urldate = {2017-09-01},

journal = {PHYSICAL CHEMISTRY CHEMICAL PHYSICS},

volume = {19},

number = {35},

pages = {24029-24041},

keywords = {NOFT, QCD-KT},

pubstate = {published},

tppubtype = {article}

}

@article{RN309,

title = {Global Method for Electron Correlation},

author = {M. Piris},

url = {<Go to ISI>://WOS:000407445800006},

doi = {10.1103/PhysRevLett.119.063002},

issn = {0031-9007},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Physical Review Letters},

volume = {119},

number = {6},

note = {Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1079-7114},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN310,

title = {Analytic gradients for natural orbital functional theory},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000393431000005},

doi = {10.1063/1.4973271},

issn = {0021-9606},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Journal of Chemical Physics},

volume = {146},

number = {1},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN306,

title = {On the performance of natural orbital functional approximations in the Hubbard model},

author = {I. Mitxelena and M. Piris and M. Rodriguez-Mayorga},

url = {<Go to ISI>://WOS:000410958500001},

doi = {10.1088/1361-648X/aa80ca},

issn = {0953-8984},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Journal of Physics-Condensed Matter},

volume = {29},

number = {42},

note = {Mitxelena, I. Piris, M. Rodriguez-Mayorga, M. 

Piris, Mario/E-7406-2010; Rodriguez Mayorga, Mauricio/AHB-2658-2022 

Piris, Mario/0000-0003-0222-2953; Rodriguez Mayorga, Mauricio/0000-0003-0869-9787; MITXELENA, ION/0000-0003-1064-5139 

1361-648x},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN307,

title = {Comment on },

author = {M. Piris and K. Pernal},

url = {<Go to ISI>://WOS:000413272300006},

doi = {10.1103/PhysRevA.96.046501},

issn = {2469-9926},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Physical Review A},

volume = {96},

number = {4},

note = {Piris, Mario Pernal, Katarzyna 

Piris, Mario/E-7406-2010; Pernal, Katarzyna/A-2120-2010 

Piris, Mario/0000-0003-0222-2953; Pernal, Katarzyna/0000-0003-1261-9065 

2469-9934},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN312,

title = {Chemical and ionization potentials: Relation via the Pauli potential and NOF theory},

author = {M. Piris and N. H. March},

url = {<Go to ISI>://WOS:000374689200003},

doi = {10.1002/qua.25039},

issn = {0020-7608},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {116},

number = {11},

pages = {805-818},

note = {Piris, M. March, N. H. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1097-461x 

Si},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN37,

title = {The Bond Order of C2 from a Strictly N-Representable Natural Orbital Energy Functional Perspective},

author = {M. Piris and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000372526500028},

doi = {10.1002/chem.201504491},

issn = {0947-6539},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Chemistry-a European Journal},

volume = {22},

number = {12},

pages = {4109-4115},

note = {Piris, Mario Lopez, Xabier Ugalde, Jesus M. 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588 

1521-3765},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN311,

title = {Potential energy curves for P-2 and P-2(+) constructed from a strictly N-representable natural orbital functional},

author = {M. Piris and N. H. March},

url = {<Go to ISI>://WOS:000382560800011},

doi = {10.1080/00319104.2016.1166364},

issn = {0031-9104},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Physics and Chemistry of Liquids},

volume = {54},

number = {6},

pages = {797-801},

note = {Piris, M. March, N. H. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1029-0451},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN313,

title = {Molecular electric moments calculated by using natural orbital functional theory},

author = {I. Mitxelena and M. Piris},

url = {<Go to ISI>://WOS:000377712700010},

doi = {10.1063/1.4951685},

issn = {0021-9606},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Journal of Chemical Physics},

volume = {144},

number = {20},

note = {Mitxelena, Ion Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953; MITXELENA, ION/0000-0003-1064-5139 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{WOS:000369806000003,

title = {Robust validation of approximate 1-matrix functionals with few-electron  harmonium atoms},

author = {Jerzy Cioslowski and Mario Piris and Eduard Matito},

doi = {10.1063/1.4936583},

issn = {0021-9606},

year  = {2015},

date = {2015-12-01},

urldate = {2015-12-01},

journal = {JOURNAL OF CHEMICAL PHYSICS},

volume = {143},

number = {21},

keywords = {NOFT, QCD-KT},

pubstate = {published},

tppubtype = {article}

}

@article{WOS:000364235800012,

title = {H4: A challenging system for natural orbital functional  approximations},

author = {Eloy Ramos-Cordoba and Xabier Lopez and Mario Piris and Eduard Matito},

doi = {10.1063/1.4934799},

issn = {0021-9606},

year  = {2015},

date = {2015-10-01},

urldate = {2015-10-01},

journal = {JOURNAL OF CHEMICAL PHYSICS},

volume = {143},

number = {16},

keywords = {NOFT, QCD-KT},

pubstate = {published},

tppubtype = {article}

}

@article{RN319,

title = {Low-Lying Isomers of Free-Space Halogen Clusters with Tetrahedral and Octahedral Symmetry in Relation to Stable Molecules Such as SF6},

author = {M. Piris and N. H. March},

url = {<Go to ISI>://WOS:000362701800008},

doi = {10.1021/acs.jpca.5b02788},

issn = {1089-5639},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {Journal of Physical Chemistry A},

volume = {119},

number = {40},

pages = {10190-10194},

note = {Piris, M. March, N. H. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN316,

title = {PNOF5 calculations based on the },

author = {X. Lopez and M. Piris},

url = {<Go to ISI>://WOS:000365330100002},

doi = {10.1007/s00214-015-1756-x},

issn = {1432-881X},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {Theoretical Chemistry Accounts},

volume = {134},

number = {12},

note = {Lopez, Xabier Piris, Mario 

Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010 

Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953 

1432-2234},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN317,

title = {Is the Hartree-Fock prediction that the chemical potential mu of non-relativistic neutral atoms is equal to minus the ionisation potential I sensitive to electron correlation?},

author = {M. Piris and N. H. March},

url = {<Go to ISI>://WOS:000357487800003},

doi = {10.1080/00319104.2015.1029478},

issn = {0031-9104},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {Physics and Chemistry of Liquids},

volume = {53},

number = {6},

pages = {696-705},

note = {Piris, M. March, N. H. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1029-0451},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN40,

title = {Performance of PNOF6 for Hydrogen Abstraction Reactions},

author = {X. Lopez and M. Piris and F. Ruiperez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000357963400005},

doi = {10.1021/acs.jpca.5b01585},

issn = {1089-5639},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {Journal of Physical Chemistry A},

volume = {119},

number = {27},

pages = {6981-6988},

note = {Lopez, Xabier Piris, Mario Ruiperez, Fernando Ugalde, Jesus M. 

Ruiperez, Fernando/H-9744-2013; Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010 

Ruiperez, Fernando/0000-0002-5585-245X; Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{WOS:000346662700002,

title = {Two new constraints for the cumulant matrix},

author = {Eloy Ramos-Cordoba and Pedro Salvador and Mario Piris and Eduard Matito},

doi = {10.1063/1.4903449},

issn = {0021-9606},

year  = {2014},

date = {2014-12-01},

urldate = {2014-12-01},

journal = {JOURNAL OF CHEMICAL PHYSICS},

volume = {141},

number = {23},

keywords = {NOFT, QCD-KT},

pubstate = {published},

tppubtype = {article}

}

@article{WOS:000349165104725,

title = {New stringent conditions for the cumulant matrix},

author = {Eduard Matito and Eloy Ramos-Cordoba and Mario Piris and Pedro Salvador},

issn = {0065-7727},

year  = {2014},

date = {2014-08-01},

urldate = {2014-08-01},

journal = {ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY},

volume = {248},

organization = {Amer Chem Soc},

note = {248th National Meeting of the American-Chemical-Society (ACS), San 

 Francisco, CA, AUG 10-14, 2014},

keywords = {NOFT, QCD-KT},

pubstate = {published},

tppubtype = {article}

}

@article{RN321,

title = {Weizsacker inhomogeneity kinetic energy term for the inhomogeneous electron liquid characterising some 30 homonuclear diatomic molecules at equilibrium and insight into Teller's theorem in Thomas-Fermi statistical theory},

author = {M. Piris and N. H. March},

url = {<Go to ISI>://WOS:000342843700011},

doi = {10.1080/00319104.2014.937865},

issn = {0031-9104},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {Physics and Chemistry of Liquids},

volume = {52},

number = {6},

pages = {804-814},

note = {Piris, M. March, N. H. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1029-0451},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN324,

title = {Assessment of the second-order perturbative corrections to PNOF5},

author = {M. Piris and F. Ruiperez and J. M. Matxain},

url = {<Go to ISI>://WOS:000333941400001},

doi = {10.1080/00268976.2013.854933},

issn = {0026-8976},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {Molecular Physics},

volume = {112},

number = {5-6},

pages = {1-8},

note = {Piris, M. Ruiperez, F. Matxain, J. M. 

Matxain, Jon M./J-8184-2014; Piris, Mario/E-7406-2010; Ruiperez, Fernando/H-9744-2013 

Matxain, Jon M./0000-0002-6342-0649; Piris, Mario/0000-0003-0222-2953; Ruiperez, Fernando/0000-0002-5585-245X 

1362-3028 

Si},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN323,

title = {Interacting pairs in natural orbital functional theory},

author = {M. Piris},

url = {<Go to ISI>://WOS:000340712200015},

doi = {10.1063/1.4890653},

issn = {0021-9606},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {Journal of Chemical Physics},

volume = {141},

number = {4},

note = {Piris, M. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN325,

title = {Natural orbital functional calculations of molecular polarizabilities and second hyperpolarizabilities. The hydrogen molecule as a test case},

author = {X. Lopez and M. Piris and M. Nakano and B. Champagne},

url = {<Go to ISI>://WOS:000328945800005},

doi = {10.1088/0953-4075/47/1/015101},

issn = {0953-4075},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {Journal of Physics B-Atomic Molecular and Optical Physics},

volume = {47},

number = {1},

note = {Lopez, Xabier Piris, Mario Nakano, Masayoshi Champagne, Benoit 

nakano, masayoshi/AAL-8624-2020; Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010 

nakano, masayoshi/0000-0002-3544-1290; Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953; CHAMPAGNE, Benoit/0000-0003-3678-8875 

1361-6455},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN46,

title = {Perspective on Natural Orbital Functional Theory},

author = {M. Piris and J. M. Ugalde},

url = {<Go to ISI>://WOS:000340530500003},

doi = {10.1002/qua.24663},

issn = {0020-7608},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {114},

number = {18},

pages = {1169-1175},

note = {Piris, Mario Ugalde, Jesus M. 

Ugalde, Jesus/M-2771-2014; Piris, Mario/E-7406-2010 

Ugalde, Jesus/0000-0001-8980-9751; Piris, Mario/0000-0003-0222-2953 

1097-461x 

Si},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN120,

title = {The natural orbital functional theory of the bonding in Cr-2, Mo-2 and W-2},

author = {F. Ruiperez and M. Piris and J. M. Ugalde and J. M. Matxain},

url = {<Go to ISI>://WOS:000313566300038},

doi = {10.1039/c2cp43559d},

issn = {1463-9076},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Physical Chemistry Chemical Physics},

volume = {15},

number = {6},

pages = {2055-2062},

note = {Ruiperez, F. Piris, M. Ugalde, J. M. Matxain, J. M. 

Piris, Mario/E-7406-2010; Ruiperez, Fernando/H-9744-2013; Matxain, Jon M./J-8184-2014; Ugalde, Jesus/M-2771-2014 

Piris, Mario/0000-0003-0222-2953; Ruiperez, Fernando/0000-0002-5585-245X; Matxain, Jon M./0000-0002-6342-0649; Ugalde, Jesus/0000-0001-8980-9751 

1463-9084},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN62,

title = {The one-electron picture in the Piris natural orbital functional 5 (PNOF5)},

author = {M. Piris and J. M. Matxain and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000318294700001},

doi = {10.1007/s00214-012-1298-4},

issn = {1432-881X},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Theoretical Chemistry Accounts},

volume = {132},

number = {2},

note = {Piris, Mario Matxain, Jon M. Lopez, Xabier Ugalde, Jesus M. 

Piris, Mario/E-7406-2010; Matxain, Jon M./J-8184-2014; Lopez, Xabier/G-5690-2015; Ugalde, Jesus/M-2771-2014 

Piris, Mario/0000-0003-0222-2953; Matxain, Jon M./0000-0002-6342-0649; Lopez, Xabier/0000-0002-2711-3588; Ugalde, Jesus/0000-0001-8980-9751 

1432-2234},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN329,

title = {A natural orbital functional based on an explicit approach of the two-electron cumulant},

author = {M. Piris},

url = {<Go to ISI>://WOS:000314216800001},

doi = {10.1002/qua.24020},

issn = {0020-7608},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {113},

number = {5},

pages = {620-630},

note = {Piris, Mario 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1097-461x 

Si},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN330,

title = {Bounds on the PNOF5 natural geminal occupation numbers},

author = {M. Piris},

url = {<Go to ISI>://WOS:000314074200019},

doi = {10.1016/j.comptc.2012.07.016},

issn = {2210-271X},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Computational and Theoretical Chemistry},

volume = {1003},

pages = {123-126},

note = {Piris, M. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1872-7999 

Si},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN60,

title = {Communication: Chemical bonding in carbon dimer isovalent series from the natural orbital functional theory perspective},

author = {J. M. Matxain and F. Ruiperez and I. Infante and X. Lopez and J. M. Ugalde and G. Merino and M. Piris},

url = {<Go to ISI>://WOS:000317814900002},

doi = {10.1063/1.4802585},

issn = {0021-9606},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Journal of Chemical Physics},

volume = {138},

number = {15},

note = {Matxain, Jon M. Ruiperez, Fernando Infante, Ivan Lopez, Xabier Ugalde, Jesus M. Merino, Gabriel Piris, Mario 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015; Ruiperez, Fernando/H-9744-2013; Merino, Gabriel/A-1046-2009; Infante, Ivan/A-1912-2011; Matxain, Jon M./J-8184-2014 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588; Ruiperez, Fernando/0000-0002-5585-245X; Infante, Ivan/0000-0003-3467-9376; Matxain, Jon M./0000-0002-6342-0649 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN328,

title = {Computational study of Be-2 using Piris natural orbital functionals},

author = {J. M. Matxain and F. Ruiperez and M. Piris},

url = {<Go to ISI>://WOS:000318274700005},

doi = {10.1007/s00894-012-1548-3},

issn = {1610-2940},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Journal of Molecular Modeling},

volume = {19},

number = {5},

pages = {1967-1972},

note = {Matxain, Jon M. Ruiperez, Fernando Piris, Mario 

Ruiperez, Fernando/H-9744-2013; Piris, Miguel A/B-7067-2008; Matxain, Jon M./J-8184-2014; Piris, Mario/E-7406-2010 

Ruiperez, Fernando/0000-0002-5585-245X; Piris, Miguel A/0000-0001-5839-3634; Matxain, Jon M./0000-0002-6342-0649; Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN327,

title = {Interpair electron correlation by second-order perturbative corrections to PNOF5},

author = {M. Piris},

url = {<Go to ISI>://WOS:000323177900011},

doi = {10.1063/1.4817946},

issn = {0021-9606},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Journal of Chemical Physics},

volume = {139},

number = {6},

note = {Piris, M. 

Piris, Mario/E-7406-2010 

Piris, Mario/0000-0003-0222-2953 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN326,

title = {The intrapair electron correlation in natural orbital functional theory},

author = {M. Piris and J. M. Matxain and X. Lopez},

url = {<Go to ISI>://WOS:000329191300009},

doi = {10.1063/1.4844075},

issn = {0021-9606},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Journal of Chemical Physics},

volume = {139},

number = {23},

note = {Piris, M. Matxain, J. M. Lopez, X. 

Lopez, Xabier/G-5690-2015; Matxain, Jon M./J-8184-2014; Piris, Mario/E-7406-2010 

Lopez, Xabier/0000-0002-2711-3588; Matxain, Jon M./0000-0002-6342-0649; Piris, Mario/0000-0003-0222-2953 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN67,

title = {Performance of PNOF5 Natural Orbital Functional for Radical Formation Reactions: Hydrogen Atom Abstraction and C-C and O-O Homolytic Bond Cleavage in Selected Molecules},

author = {X. Lopez and F. Ruiperez and M. Piris and J. M. Matxain and E. Matito and J. M. Ugalde},

url = {<Go to ISI>://WOS:000307478800011},

doi = {10.1021/ct300414t},

issn = {1549-9618},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Journal of Chemical Theory and Computation},

volume = {8},

number = {8},

pages = {2646-2652},

note = {Lopez, Xabier Ruiperez, Fernando Piris, Mario Matxain, Jon M. Matito, Eduard Ugalde, Jesus M. 

Matito, Eduard/A-6532-2009; Ugalde, Jesus/M-2771-2014; Ruiperez, Fernando/H-9744-2013; Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010; Matxain, Jon M./J-8184-2014 

Matito, Eduard/0000-0001-6895-4562; Ugalde, Jesus/0000-0001-8980-9751; Ruiperez, Fernando/0000-0002-5585-245X; Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953; Matxain, Jon M./0000-0002-6342-0649 

1549-9626},

keywords = {NOFT, QCD-KT},

pubstate = {published},

tppubtype = {article}

}

@article{RN71,

title = {sp(3) Hybrid orbitals and ionization energies of methane from PNOF5},

author = {J. M. Matxain and M. Piris and J. M. Mercero and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000301931800052},

doi = {10.1016/j.cplett.2012.02.041},

issn = {0009-2614},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Chemical Physics Letters},

volume = {531},

pages = {272-274},

note = {Matxain, Jon M. Piris, Mario Mercero, Jose M. Lopez, Xabier Ugalde, Jesus M. 

Ugalde, Jesus/M-2771-2014; Piris, Mario/E-7406-2010; Mercero, Jose/E-6828-2010; Matxain, Jon M./J-8184-2014; Lopez, Xabier/G-5690-2015 

Ugalde, Jesus/0000-0001-8980-9751; Piris, Mario/0000-0003-0222-2953; Mercero, Jose/0000-0003-4857-6685; Matxain, Jon M./0000-0002-6342-0649; Lopez, Xabier/0000-0002-2711-3588 

1873-4448},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN70,

title = {The extended Koopmans' theorem: Vertical ionization potentials from natural orbital functional theory},

author = {M. Piris and J. M. Matxain and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000303935700017},

doi = {10.1063/1.4709769},

issn = {0021-9606},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Journal of Chemical Physics},

volume = {136},

number = {17},

note = {Piris, Mario Matxain, Jon M. Lopez, Xabier Ugalde, Jesus M. 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Matxain, Jon M./J-8184-2014; Lopez, Xabier/G-5690-2015 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Matxain, Jon M./0000-0002-6342-0649; Lopez, Xabier/0000-0002-2711-3588 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN69,

title = {The Nature of Chemical Bonds from PNOF5 Calculations},

author = {J. M. Matxain and M. Piris and J. Uranga and X. Lopez and G. Merino and J. M. Ugalde},

url = {<Go to ISI>://WOS:000305131000011},

doi = {10.1002/cphc.201200205},

issn = {1439-4235},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Chemphyschem},

volume = {13},

number = {9},

pages = {2297-2303},

note = {Matxain, Jon M. Piris, Mario Uranga, Jon Lopez, Xabier Merino, Gabriel Ugalde, Jesus M. 

Lopez, Xabier/G-5690-2015; Matxain, Jon M./J-8184-2014; Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Uranga, Jon/ABC-3945-2021; Merino, Gabriel/A-1046-2009 

Lopez, Xabier/0000-0002-2711-3588; Matxain, Jon M./0000-0002-6342-0649; Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Uranga, Jon/0000-0002-1256-6656; 

1439-7641},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN129,

title = {A natural orbital functional for multiconfigurational states},

author = {M. Piris and X. Lopez and F. Ruiperez and J. M. Matxain and J. M. Ugalde},

url = {<Go to ISI>://WOS:000290047600003},

doi = {10.1063/1.3582792},

issn = {0021-9606},

year  = {2011},

date = {2011-01-01},

urldate = {2011-01-01},

journal = {Journal of Chemical Physics},

volume = {134},

number = {16},

note = {Piris, M. Lopez, X. Ruiperez, F. Matxain, J. M. Ugalde, J. M. 

Ugalde, Jesus/M-2771-2014; Matxain, Jon M./J-8184-2014; Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010; Ruiperez, Fernando/H-9744-2013 

Ugalde, Jesus/0000-0001-8980-9751; Matxain, Jon M./0000-0002-6342-0649; Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953; Ruiperez, Fernando/0000-0002-5585-245X 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN83,

title = {Diradicals and Diradicaloids in Natural Orbital Functional Theory},

author = {X. Lopez and F. Ruiperez and M. Piris and J. M. Matxain and J. M. Ugalde},

url = {<Go to ISI>://WOS:000289264400007},

doi = {10.1002/cphc.201100136},

issn = {1439-4235},

year  = {2011},

date = {2011-01-01},

urldate = {2011-01-01},

journal = {Chemphyschem},

volume = {12},

number = {6},

pages = {1061-1065},

note = {Lopez, Xabier Ruiperez, Fernando Piris, Mario Matxain, Jon M. Ugalde, Jesus M. 

Ugalde, Jesus/M-2771-2014; Ruiperez, Fernando/H-9744-2013; Matxain, Jon M./J-8184-2014; Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010 

Ugalde, Jesus/0000-0001-8980-9751; Ruiperez, Fernando/0000-0002-5585-245X; Matxain, Jon M./0000-0002-6342-0649; Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN131,

title = {Homolytic molecular dissociation in natural orbital functional theory},

author = {J. M. Matxain and M. Piris and F. Ruiperez and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000296871500014},

doi = {10.1039/c1cp21696a},

issn = {1463-9076},

year  = {2011},

date = {2011-01-01},

urldate = {2011-01-01},

journal = {Physical Chemistry Chemical Physics},

volume = {13},

number = {45},

pages = {20129-20135},

note = {Matxain, J. M. Piris, M. Ruiperez, F. Lopez, X. Ugalde, J. M. 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Matxain, Jon M./J-8184-2014; Ruiperez, Fernando/H-9744-2013; Lopez, Xabier/G-5690-2015 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Matxain, Jon M./0000-0002-6342-0649; Ruiperez, Fernando/0000-0002-5585-245X; Lopez, Xabier/0000-0002-2711-3588 

1463-9084},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN80,

title = {Natural Orbital Functional Theory and Reactivity Studies of Diradical Rearrangements: Ethylene Torsion as a Case Study},

author = {X. Lopez and M. Piris and J. M. Matxain and F. Ruiperez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000292213000014},

doi = {10.1002/cphc.201100190},

issn = {1439-4235},

year  = {2011},

date = {2011-01-01},

urldate = {2011-01-01},

journal = {Chemphyschem},

volume = {12},

number = {9},

pages = {1673-1676},

note = {Lopez, Xabier Piris, Mario Matxain, Jon M. Ruiperez, Fernando Ugalde, Jesus M. 

Ruiperez, Fernando/H-9744-2013; Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010; Matxain, Jon M./J-8184-2014 

Ruiperez, Fernando/0000-0002-5585-245X; Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953; Matxain, Jon M./0000-0002-6342-0649 

1439-7641},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN133,

title = {Communication: The role of the positivity N-representability conditions in natural orbital functional theory},

author = {M. Piris and J. M. Matxain and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000282047500001},

doi = {10.1063/1.3481578},

issn = {0021-9606},

year  = {2010},

date = {2010-01-01},

urldate = {2010-01-01},

journal = {Journal of Chemical Physics},

volume = {133},

number = {11},

note = {Piris, M. Matxain, J. M. Lopez, X. Ugalde, J. M. 

Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Matxain, Jon M./J-8184-2014 

Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Matxain, Jon M./0000-0002-6342-0649 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN135,

title = {Communications: Accurate description of atoms and molecules by natural orbital functional theory},

author = {M. Piris and J. M. Matxain and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000273890800003},

doi = {10.1063/1.3298694},

issn = {0021-9606},

year  = {2010},

date = {2010-01-01},

urldate = {2010-01-01},

journal = {Journal of Chemical Physics},

volume = {132},

number = {3},

note = {Piris, M. Matxain, J. M. Lopez, X. Ugalde, J. M. 

Lopez, Xabier/G-5690-2015; Ugalde, Jesus/M-2771-2014; Matxain, Jon M./J-8184-2014; Piris, Mario/E-7406-2010 

Lopez, Xabier/0000-0002-2711-3588; Ugalde, Jesus/0000-0001-8980-9751; Matxain, Jon M./0000-0002-6342-0649; Piris, Mario/0000-0003-0222-2953 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN132,

title = {Complete basis set limit extrapolation calculations with PNOF3},

author = {J. M. Matxain and M. Piris and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000282698700034},

doi = {10.1016/j.cplett.2010.09.004},

issn = {0009-2614},

year  = {2010},

date = {2010-01-01},

urldate = {2010-01-01},

journal = {Chemical Physics Letters},

volume = {499},

number = {1-3},

pages = {164-167},

note = {Matxain, J. M. Piris, M. Lopez, X. Ugalde, J. M. 

Lopez, Xabier/G-5690-2015; Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Matxain, Jon M./J-8184-2014 

Lopez, Xabier/0000-0002-2711-3588; Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Matxain, Jon M./0000-0002-6342-0649 

1873-4448},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN136,

title = {Performance of PNOF3 for reactivity studies: X BO and X CN isomerization reactions (X = H, Li) as a case study},

author = {X. Lopez and M. Piris and J. M. Matxain and J. M. Ugalde},

url = {<Go to ISI>://WOS:000282642800004},

doi = {10.1039/c003379k},

issn = {1463-9076},

year  = {2010},

date = {2010-01-01},

urldate = {2010-01-01},

journal = {Physical Chemistry Chemical Physics},

volume = {12},

number = {40},

pages = {12931-12934},

note = {Lopez, X. Piris, M. Matxain, J. M. Ugalde, J. M. 

Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015; Matxain, Jon M./J-8184-2014; Piris, Mario/E-7406-2010 

Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588; Matxain, Jon M./0000-0002-6342-0649; Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN137,

title = {Iterative Diagonalization for Orbital Optimization in Natural Orbital Functional Theory},

author = {M. Piris and J. M. Ugalde},

url = {<Go to ISI>://WOS:000269095700012},

doi = {10.1002/jcc.21225},

issn = {0192-8651},

year  = {2009},

date = {2009-01-01},

urldate = {2009-01-01},

journal = {Journal of Computational Chemistry},

volume = {30},

number = {13},

pages = {2078-2086},

note = {Piris, M. Ugalde, J. M. 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751 

1096-987x},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN138,

title = {Spin conserving natural orbital functional theory},

author = {M. Piris and J. M. Matxain and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000267983100002},

doi = {10.1063/1.3180958},

issn = {0021-9606},

year  = {2009},

date = {2009-01-01},

urldate = {2009-01-01},

journal = {Journal of Chemical Physics},

volume = {131},

number = {2},

note = {Piris, M. Matxain, J. M. Lopez, X. Ugalde, J. M. 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015; Matxain, Jon M./J-8184-2014 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588; Matxain, Jon M./0000-0002-6342-0649},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN140,

title = {Correlation holes for the helium dimer},

author = {M. Piris and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000254778800002},

doi = {10.1063/1.2883959},

issn = {0021-9606},

year  = {2008},

date = {2008-01-01},

urldate = {2008-01-01},

journal = {Journal of Chemical Physics},

volume = {128},

number = {13},

note = {Piris, M. Lopez, X. Ugalde, J. M. 

Piris, Mario/E-7406-2010; Ugalde, Jesus/M-2771-2014; Lopez, Xabier/G-5690-2015 

Piris, Mario/0000-0003-0222-2953; Ugalde, Jesus/0000-0001-8980-9751; Lopez, Xabier/0000-0002-2711-3588 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN97,

title = {Natural orbital functional description of van der Waals interactions. A case study of the effect of the basis set for the helium dimer},

author = {M. Piris and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000256689900007},

doi = {10.1002/qua.21572},

issn = {0020-7608},

year  = {2008},

date = {2008-01-01},

urldate = {2008-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {108},

number = {10},

pages = {1660-1663},

note = {Piris, Mario Lopez, Xabier Ugalde, Jesus M. 

33rd Congress of Theoretical Chemists of Latin Expression 

Sep 17-21, 2007 

Univ Havana, Havana, CUBA 

Piris, Mario/E-7406-2010; Lopez, Xabier/G-5690-2015; Ugalde, Jesus/M-2771-2014 

Piris, Mario/0000-0003-0222-2953; Lopez, Xabier/0000-0002-2711-3588; Ugalde, Jesus/0000-0001-8980-9751 

1097-461x},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN139,

title = {Piris natural orbital functional study of the dissociation of the radical helium dimer},

author = {M. Piris and J. M. Matxain and J. M. Ugalde},

url = {<Go to ISI>://WOS:000257468100013},

doi = {10.1063/1.2950094},

issn = {0021-9606},

year  = {2008},

date = {2008-01-01},

urldate = {2008-01-01},

journal = {Journal of Chemical Physics},

volume = {129},

number = {1},

note = {Piris, M. Matxain, J. M. Ugalde, J. M. 

Ugalde, Jesus/M-2771-2014; Piris, Mario/E-7406-2010; Matxain, Jon M./J-8184-2014 

Ugalde, Jesus/0000-0001-8980-9751; Piris, Mario/0000-0003-0222-2953; Matxain, Jon M./0000-0002-6342-0649 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN98,

title = {Electron-pair density relaxation holes},

author = {M. Piris and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000256527500006},

doi = {10.1063/1.2937456},

issn = {0021-9606},

year  = {2008},

date = {2008-01-01},

urldate = {2008-01-01},

journal = {Journal of Chemical Physics},

volume = {128},

number = {21},

note = {Piris, Mario Lopez, Xabier Ugalde, Jesus M. 

Lopez, Xabier/G-5690-2015; Ugalde, Jesus/M-2771-2014; Piris, Mario/E-7406-2010 

Lopez, Xabier/0000-0002-2711-3588; Ugalde, Jesus/0000-0001-8980-9751; Piris, Mario/0000-0003-0222-2953},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}

@article{RN144,

title = {Dispersion interactions within the Piris natural orbital functional theory: The helium dimer},

author = {M. Piris and X. Lopez and J. M. Ugalde},

url = {<Go to ISI>://WOS:000247106600007},

doi = {10.1063/1.2743019},

issn = {0021-9606},

year  = {2007},

date = {2007-01-01},

urldate = {2007-01-01},

journal = {Journal of Chemical Physics},

volume = {126},

number = {21},

note = {Piris, M. Lopez, X. Ugalde, J. M. 

Piris, Mario/E-7406-2010; Lopez, Xabier/G-5690-2015; Ugalde, Jesus/M-2771-2014 

Piris, Mario/0000-0003-0222-2953; Lopez, Xabier/0000-0002-2711-3588; Ugalde, Jesus/0000-0001-8980-9751 

1089-7690},

keywords = {NOFT},

pubstate = {published},

tppubtype = {article}

}