DEDICATED MOLECULAR-ORBITALS FOR THE VARIATIONAL DETERMINATION OF THEELECTRON-TRANSFER MATRIX ELEMENT - METHOD AND APPLICATION TO A CU(I)-CU(II) MIXED-VALENCE COMPOUND
Cj. Calzado et al., DEDICATED MOLECULAR-ORBITALS FOR THE VARIATIONAL DETERMINATION OF THEELECTRON-TRANSFER MATRIX ELEMENT - METHOD AND APPLICATION TO A CU(I)-CU(II) MIXED-VALENCE COMPOUND, The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 101(9), 1997, pp. 1716-1721
A method to obtain molecular orbitals specially suited for the variati
onal calculation of the electron-transfer matrix element V-ab is repor
ted. These electron-transfer dedicated molecular orbitals (ET-DMOs) ar
e determined from the diagrammatic second-order expansion of the trans
fer integral H-ab and are associated to a participation index which al
lows for a truncation of the molecular orbital basis set and, therefor
e, for a reduction of the variational space in a difference-dedicated
configuration interaction (DDCI) calculation. The suitability of these
ET-DMOs is first tested with some simple organic models for which a r
eduction of the second-order space of 40-60% is possible without signi
ficant loss of precision. The calculation of the transfer integral for
a Cu(I)-Cu(II) mixed-valence system is also reported. Using as model
a cluster of formula Cu2Cl63-, H-ab is estimated to be 2000 cm(-1) fro
m a perturbational-variational calculation. The stability of the ET-DM
Os for this system is found to be excellent allowing for a reduction o
f the variational space of 76% with a relative error of only 0.15%.