Jp. Blaudeau et al., EXTENSION OF GAUSSIAN-2 (G2) THEORY TO MOLECULES CONTAINING 3RD-ROW ATOMS K AND CA, The Journal of chemical physics, 107(13), 1997, pp. 5016-5021
Gaussian-2 (G2) theory has been extended to molecules containing the t
hird-row nontransition elements K and Ca. Basis sets compatible with t
hose used in G2 theory for molecules containing first-and second-row a
toms, as well as the third-row elements Ga-Kr, have been derived. As f
or Ga-Kr, first-order spin-orbit corrections are included explicitly i
n the G2 energies of K-and Ca-containing atoms and molecules. In contr
ast to the procedure for Ga-Kr, the 3s and 3p orbitals need to be incl
uded in the cell-elation space for K-and Ca-containing molecules. The
geometries obtained with the new basis sets are in satisfactory agreem
ent with experiment. Assessment of the thermochemical predictions is l
imited because of the sparsity of accurate experimental data for molec
ules containing K and Ca, Ionization energies are generally in good ag
reement with experimental values, as are the atomization energies for
K-containing molecules. However. there are larger differences between
theoretical and experimental atomization energies for Ca-containing mo
lecules. (C) 1997 American Institute of Physics.