DENSITY-FUNCTIONAL INVESTIGATION OF THE MOLECULAR GEOMETRIES, HARMONIC VIBRATIONAL FREQUENCIES, SINGLET-TRIPLET ENERGY SEPARATIONS, ADIABATIC IONIZATION-POTENTIALS, AND ELECTRON-AFFINITIES OF XY(2) (X=SI, GE, SN, Y=F, CL) SYSTEMS

The geometrical and spectroscopic parameters of SiF2, SiCl2, GeF2, GeC l2, SnF2, and SnCl2 were determined using the linear combination of Ga ussian-type orbitals-local spin density (LCGTO-LSD) method and employi ng both the local (LSD) and nonlocal functionals (NLSD) for the exchan ge-correlation energy. A general good agreement with available experim ental information and with previous high-level correlated computations was found. Data on cations and anions are reported for the first time and can be used, together with those on neutral systems, to stimulate future and desirable experimental work on this significant class of m olecules. (C) 1997 John Wiley & Sons, Inc.