87. J. M. Mercero, J. M. Elorza, J. M. Ugalde, R. J.  Boyd, “Electronic structures of the bound excited quartet states of the helium anion“, Physical Review A, vol.60, iss.6, p.4375-4378, (1999) . DOI: 10.1103/PhysRevA.60.4375

86. J. E. Fowler, A. García, J. M. Ugalde, “Many low-lying isomers of the cationic and neutral niobium trimer and tetramer“, Physical Review A, vol.60, iss.4, p.3058-3070, (1999) . DOI: 10.1103/PhysRevA.60.3058

85. A. Irigoras, J. E. Fowler, J. M. Ugalde, “Reactivity of Cr+(6S,4D), Mn+(7S,5S), and Fe+(6D,4F): Reaction of Cr+, Mn+, and Fe+ with Water“, Journal of the American Chemical Society, vol.121, iss.37, p.8549-8558, (1999) . DOI: 10.1021/ja984469u

84. C. Sarasola, J. E. Fowler, J. M. Ugalde, “Critical conditions for stable dipole-bound dianions“, The Journal of Chemical Physics, vol.110, iss.24, p.11717-11719, (1999) . DOI: 10.1063/1.479117

83. J. M. Mercero, J. E. Fowler, C. Sarasola, J. M. Ugalde, “Atomic configuration-interaction electron-electron counterbalance densities“, Physical Review A, vol.59, iss.6, p.4255-4258, (1999) . DOI: 10.1103/PhysRevA.59.4255

82. X. Fradera, C. Sarasola, J. M. Ugalde, R. J. Boyd, “The topological features of the intracule density of the uniform electron gas“, Chemical Physics Letters, vol.304, iss.5-6, p.393-398, (1999) . DOI: 10.1016/S0009-2614(99)00310-3

81. A. García, J. M. Elorza, J. M. Ugalde, “Density functional studies of the pseudo-.a charge-transfer complex between cyclopropane and chlorine monofluoride“, Physical Chemistry Chemical Physics, vol.1, iss.9, p.2203-2207, (1999) . DOI: 10.1039/A901066A

80. A. Irigoras, J. E. Fowler, J. M. Ugalde, “Reactivity of Sc+(3D,1D) and V+(5D,3F):  Reaction of Sc+ and V+ with Water“, Journal of the American Chemical Society, vol.121, iss.3, p.574-580, (1999) . DOI: 10.1021/ja9805829

79. A. García, J. M. Elorza, J. M. Ugalde, “Density Functional Studies of the n·aσ Charge-Transfer Complex between Sulfur Dioxide and Chlorine Monofluoride“, The Journal of Physical Chemistry A, vol.102, iss.45, p.8974-8978, (1998) . DOI: 10.1021/jp981988a

78. J. M. Mercero, J. E. Fowler, J. M. Ugalde, “Aluminum(III) Interactions with the Acidic Amino Acid Chains“, The Journal of Physical Chemistry A, vol.102, iss.35, p.7006-7012, (1998) . DOI: 10.1021/jp981146b

77. J. E. Fowler, J. M. Ugalde, “Al12 and the Al@Al12 clusters“, Physical Review A, vol.58, iss.1, p.383-388, (1998) . DOI: 10.1103/PhysRevA.58.383

76. J. M. Mercero, J. E. Fowler, C. Sarasola, J. M. Ugalde, “Bound excited states of H^{-} and He^{-} in the statically screened Coulomb potential“, Physical Review A, vol.57, iss.4, p.2550-2555, (1998) . DOI: 10.1103/PhysRevA.57.2550

75. C. Sarasola, J. M. Elorza, J. M. Ugalde, “On the oxidation state of the guest atom in endohedral metallofullerene complexes“, Chemical Physics Letters, vol.285, iss.3-4, p.226-229, (1998) . DOI: 10.1016/S0009-2614(98)00038-4

74. A. Irigoras, J. E. Fowler, J. M. Ugalde, “On the Reactivity of Ti+(4F,2F). Reaction of Ti+ with OH2 (vol 102A, p. 293, 1998)”, The Journal of Physical Chemistry A, vol.102, iss.12, p.2252-2252, (1998) . DOI: 10.1021/jp980734m

73. A. García, J. M. Mercero, J. E. Fowler, J. M. Ugalde, “Molecular and Electronic Structures of (TiXH6)0/-, X = B, Al, Ga, Compounds“, The Journal of Physical Chemistry A, vol.102, iss.11, p.2055-2064, (1998) . DOI: 10.1021/jp973365n

72. S. K. Worsnop, R. J. Boyd, C. Sarasola, J. M. Ugalde, “A spin-density polarization index“, The Journal of Chemical Physics, vol.108, iss.7, p.2824-2830, (1998) . DOI: 10.1063/1.475673

71. C. Sarasola, J. M. Elorza, J.M. Ugalde, “Closed‐form analytical solutions for the calculation of the moments of the molecular electron density“, Journal of Mathematical Chemistry, vol.23, iss.3/4, p.405-414, (1998) . DOI: 10.1023/A:1019145913874

70. A. Irigoras, J. E. Fowler, J. M. Ugalde, “On the Reactivity of Ti+(4F,2F). Reaction of Ti+ with OH2“, The Journal of Physical Chemistry A, vol.102, iss.1, p.293-300, (1998) . DOI: 10.1021/jp973143p

69. K. Eder, D. Semrad, P. Bauer, R. Golser, P. Maier-Komor, F. Aumayr, M. Pealba, A. Arnau, J. M. Ugalde, P. M. Echenique, “Absence of a “Threshold Effect” in the Energy Loss of Slow Protons Traversing Large-Band-Gap Insulators“, Physical Review Letters, vol.79, iss.21, p.4112-4115, (1997) . DOI: 10.1103/PhysRevLett.79.4112

68. A. García, J. M. Mercero, J. M. Ugalde, “Molecular and Electronic Structures of TiXH6+ (X = B, Al, Ga) Compounds“, The Journal of Physical Chemistry A, vol.101, iss.33, p.5953-5957, (1997) . DOI: 10.1021/jp9712720

67. J. M. Ugalde, C. Sarasola, X. Lopez, “Atomic and molecular bound ground states of the Yukawa potential“, Physical Review A, vol.56, iss.2, p.1642-1645, (1997) . DOI: 10.1103/PhysRevA.56.1642

66. J. M. Mercero, X. Lopez, J. E. Fowler, J. M. Ugalde, ““, The Journal of Physical Chemistry A, vol.101, iss.30, p.5574-5579, (1997) . DOI: 10.1021/jp970585s

65. E. M. Cruz, J. E. Fowler, X. Lopez, J. M. Ugalde, “Reaction of P+ (3P) with Methylamine:  A Detailed Study of the Potential Energy Surface and Reaction Mechanisms“, The Journal of Physical Chemistry A, vol.101, iss.26, p.4807-4813, (1997) . DOI: 10.1021/jp970396%2B

64. A. García, Elso M. Cruz, C. Sarasola, J. M. Ugalde, “Properties of some weakly bound complexes obtained with various density functionals“, Journal of Molecular Structure: THEOCHEM, vol.397, iss.1-3, p.191-197, (1997) . DOI: 10.1016/S0166-1280(96)04948-2

63. A García, E. M. Cruz, C. Sarasola, J. M. Ugalde, “Density Functional Studies of the bπ.aσ Charge-Transfer Complex Formed between Ethyne and Chlorine Monofluoride“, The Journal of Physical Chemistry A, vol.101, iss.16, p.3021-3024, (1997) . DOI: 10.1021/jp9628646

62. J. M. Ugalde, C. Sarasola, “Evaluation of screened nuclear attraction and electron repulsion molecular integrals over Gaussian basis functions“, International Journal of Quantum Chemistry, vol.62, iss.3, p.273-278, (1997) . DOI: 10.1002/(SICI)1097-461X(1997)62:33.0.CO;2-T

61. E. M. Cruz, X. Lopez, M. Ayerbe, J. M. Ugalde, “G2 Study of the Triplet and Singlet [H3, P2]+ Potential Energy Surfaces. Mechanisms for the Reaction of P+(1D,3P) with PH3“, The Journal of Physical Chemistry A, vol.101, iss.11, p.2166-2172, (1997) . DOI: 10.1021/jp962357o

60. X. Lopez, C. Sarasola, J. M. Ugalde, “Transition Energies and Emission Oscillator Strengths of Helium in Model Plasma Environments“, The Journal of Physical Chemistry A, vol.101, iss.10, p.1804-1807, (1997) . DOI: 10.1021/jp9623103

59. E. M. Cruz, X. Lopez, M. Sarobe, F. P. Cossío, J. M. Ugalde, “G2 study of triplet [H4, Si, P]+ potential energy surface: Mechanism for reaction of P+ (3P) with silane“, Journal of Computational Chemistry, vol.18, iss.1, p.9-19, (1997) . DOI: 10.1002/(SICI)1096-987X(19970115)18:1<9::AID-JCC2>3.0.CO;2-U

58. J. M. Elorza, J. M. Ugalde, “Theoretical study of the PSi2 radical”, Canadian Journal of Chemistry, vol.74, iss.12, p.2476-2480, (1996) . DOI: 10.1139/v96-277

57. A. Irigoras, J. M. Ugalde, X. Lopez, C. Sarasola, “On the dissociation energy of Ti(OH(OH2)+. An MCSCF, CCSD(T), and DFT study“, Canadian Journal of Chemistry, vol.74, iss.10, p.1824-1829, (1996) . DOI: 10.1139/v96-203

56. J. Ugalde, C. Sarasola, “Bound electronic states in a statically screened electric-dipole potential“, Physical Review A, vol.54, iss.4, p.2868-2873, (1996) . DOI: 10.1103/PhysRevA.54.2868

55. A. García, J. M. Ugalde, “On the Molecular and Electronic Structures of the H3TiTiH3 Species“, The Journal of Physical Chemistry, vol.100, iss.30, p.12277-12279, (1996) . DOI: 10.1021/jp953779l

54. G. Roa, J. M. Ugalde, F. P. Cossío, “Ab Initio Studies on the Structure of Silyl Isocyanate in the Gas Phase, in Solution, and in the Crystalline State“, The Journal of Physical Chemistry, vol.100, iss.23, p.9619-9623, (1996) . DOI: 10.1021/jp9530764

53. X. Lopez, J. M. Ugalde, C. Sarasola, F. P. Cossio, “On the accuracy of density functional theory for ionmolecule clusters. A case study of PLn+ clusters of the first and second row hydrides“, Canadian Journal of Chemistry, vol.74, iss.6, p.1032-1048, (1996) . DOI: 10.1139/v96-116

52. A. Irigoras, F. P. Cossío, C. Sarasola, J. M. Ugalde, “Ab Initio Characterization of Gaseous (HnP< >C)+ Species”, The Journal of Physical Chemistry, vol.100, iss.21, p.8758-8762, (1996) . DOI: 10.1021/jp953533g

51. B. Lecea, I. Arrastia, A. Arrieta, G. Roa, X. Lopez, M. I. Arriortua, J. M. Ugalde, F. P. Cossío, “Solvent and Substituent Effects in the Periselectivity of the Staudinger Reaction between Ketenes and ,-Unsaturated Imines. A Theoretical and Experimental Study“, The Journal of Organic Chemistry, vol.61, iss.9, p.3070-3079, (1996) . DOI: 10.1021/jo951867w

50. A. García, E. M. Cruz, C. Sarasola, J. M. Ugalde, “Performance of Becke’s exchange functional fitted for Gaussian basis sets“, Journal of Molecular Structure: THEOCHEM, vol.363, iss.3, p.279-290, (1996) . DOI: 10.1016/0166-1280(95)04450-7

49. X. Lopez, J. M. Ugalde, F. P. Cossío, “Characterization of (P+Lx)Ly Ion Molecule Clusters of First-Row Hydrides”,  Journal of the American Chemical Society, vol.118, iss.11, p.2718-2725, (1996) . DOI: 10.1021/ja952257g

48. F. P. Cossío, G. Roa, B. Lecea, J. M. Ugalde, “Substituent and Solvent Effects in the [2 + 2] Cycloaddition Reaction between Olefins and Isocyanates“, Journal of the American Chemical Society, vol.117, iss.49, p.12306-12313, (1995) . DOI: 10.1021/ja00154a033

47. B. Lecea, A. Arrieta, X. Lopez, J. M. Ugalde, F. P. Cossío, “On the Stereochemical Outcome of the Catalyzed and Uncatalyzed Cycloaddition Reaction between Activated Ketenes and Aldehydes to form cis- and trans-2-Oxetanones. An ab Initio Study“, Journal of the American Chemical Society, vol.117, iss.49, p.12314-12321, (1995) . DOI: 10.1021/ja00154a034

46. E. M. Cruz, X. Lopez, J. M. Ugalde, F. P. Cossio, “G1 and G2 Study of the Triplet [H4, C, O, P]+ Potential Energy Surface. Mechanisms for the Reaction of P+ (3P) with Methanol“, The Journal of Physical Chemistry, vol.99, iss.32, p.12170-12178, (1995) . DOI: 10.1021/j100032a019

45. X. Lopez, M. Ayerbe, J. M. Ugalde, F. P. Cossío, “Mechanisms for the Reaction of Triplet P+ with XH (X = Cl, F). Formation of the P-X Bond“, The Journal of Physical Chemistry, vol.99, iss.18, p.6812-6818, (1995) . DOI: 10.1021/j100018a010

44. A. Largo, C. Barrientos, X. Lopez, F. P. Cossío, J. M. Ugalde, “Theoretical Studies of Possible Processes for the Interstellar Production of Phosphorus Compounds. The Reaction of P+ with Acetylene“, The Journal of Physical Chemistry, vol.99, iss.17, p.6432-6440, (1995) . DOI: 10.1021/j100017a023