title: Homolytic molecular dissociation in natural orbital functional theory.
abstract: The dissociation of diatomic molecules of the 14-electron isoelectronic series N(2), O(2)(2+), CO, CN(-) and NO(+) is examined using the Piris natural orbital functional. It is found that the method describes correctly the dissociation limit yielding an integer number of electrons on the dissociated atoms, in contrast to the fractional charges obtained when using the variational two-particle reduced density matrix method under the D, Q and G positivity necessary N-representability conditions. The chemistry of the considered systems is discussed in terms of their dipole moments, natural orbital occupations and bond orders as well as atomic Mulliken populations at the dissociation limit. The values obtained agree well with accurate multiconfigurational wave function based CASSCF results and the available experimental data.
authors: Faculty of Chemistry, University of the Basque Country UPV/EHU, and Donostia International Physics Center, P.K. 1072, 20080 Donostia, Euskadi, Spain. jonmattin.matxain@ehu.es
authors: J M
authors: JM
authors: Matxain
authors: M
authors: M
authors: Piris
authors: F
authors: F
authors: Ruipérez
authors: X
authors: X
authors: Lopez
authors: J M
authors: JM
authors: Ugalde