The rapid progress in electronic structure theory and computer technology during the last two decades has made possible the determination of accurate wave functions for small and medium size molecules. However, this is only the first step in solving problems of chemical interest as most application of quantum mechanics in chemistry deal with the computation of expectation values or density functions in terms of which the properties of sought are rationalized. This requirement is closely related with one of the major challenges of quantum chemistry: the development of practical procedures for the extraction of chemically interesting information from N-electron wavefunctions.

We have succeeded in generating a full package of programs that allow for the analysis of Configuration Interaction and Hartree-Fock molecular and atomic wavefunctions in terms of one- and two-electron density functions in coordinate space. Drop us a note if you are interested in downloading the package.

Please refer to the following publications for more information:

  • J. M. Ugalde, R. J. Boyd, Angular aspects of exchange correlation and the fermi hole , Int. J. Quantum Chem. 27, 439 (1985).
  • J. M. Ugalde, R. J. Boyd, The radius of the Fermi hole in atoms, J. Phys. B 18, L701 (1985).
  • J.M. Ugalde, R.J. Boyd, On the relationship between the electron-pair distribution function and the electron correlation, Int. J. Quantum Chem. 29, 1 (1986).
  • J. M. Ugalde, R. J. Boyd, J. S. Perkyns, Angular aspects of electron correlation and the Coulomb hole, J. Chem. Phys. 87, 1216 (1987).
  • C. Sarasola, J.M. Ugalde , R.J. Boyd, The evaluation of extracule and intracule densities in the first row hydrides LiH, BeH, BH, CH, NH, OH and FH, from self-consistent field molecular wave functions, J. Phys. B 23, 1095 (1990).
  • J. M. Ugalde, C. Sarasola, L. Dominguez, R. J. Boyd, The evaluation of electronic extracule and intracule densities and related probability functions in terms of Gaussian basis functions, J. Math. Chem. 6, 51 (1991)
  • J. M. Ugalde, C. Sarasola, Upper bounds to the electron-electron coalescence density in terms of the one-electron density function, Phys. Rev. A 49, 3081 (1994).
  • J. M. Mercero, J. E. Fowler, C. Sarasola, J. M. Ugalde, Atomic configuration-interaction electron-electron counterbalance densities, Phys. Rev. A 59, 4255 (1999).
  • E. Valderrama, J. M. Mercero, J. M. Ugalde, The separation of the dynamical and non-dynamical electron correlation effects, J. Phys. B 34, 275 (2001).
  • E. Valderrama, X. Fradera, J. M. Ugalde, Electron-electron counterbalance density for molecules: exchange and correlation effects, J. Chem. Phys. 115, 1987 (2001).
  • E. Valderrama, J. M. Ugalde, Role of electron-electron coalescence density in density functional theory, Int. J. Quantum Chem. 86, 40 (2002).
  • E. V. Ludeña, J. M. Ugalde, X. Lopez, J. Fernández-Rico, G. Ramírez, A reinterpretation of the nature of the Fermi hole, J. Chem. Phys. 120, 540 (2004).
  • E.G. Valderrama, J.M. Ugalde, Electron correlation studies by means of local-scaling transformations and electron-pair density functions, J. Math. Chem. 37, 211 (2005).
  • M. Piris, X. Lopez, J.M. Ugalde, Electron-pair relaxation holes, J. Chem. Phys. 128, 214105 (2008).
  • M. Piris, X. Lopez, J.M. Ugalde, Correlation holes for the helium dimer, J. Chem. Phys. 128, 134102 (2008).