FULL VALENCE COMPLETE ACTIVE SPACE SCF, MULTIREFERENCE CI, AND DENSITY-FUNCTIONAL CALCULATIONS OF 1A1-3B1 SINGLET-TRIPLET GAPS FOR THE VALENCE-ISOELECTRONIC SERIES BH2-, CH2, NH2-, SIH2, PH2+, GAH2-, GEH2, ANDASH2+(, ALH2)
Cj. Cramer et al., FULL VALENCE COMPLETE ACTIVE SPACE SCF, MULTIREFERENCE CI, AND DENSITY-FUNCTIONAL CALCULATIONS OF 1A1-3B1 SINGLET-TRIPLET GAPS FOR THE VALENCE-ISOELECTRONIC SERIES BH2-, CH2, NH2-, SIH2, PH2+, GAH2-, GEH2, ANDASH2+(, ALH2), Chemical physics letters, 218(5-6), 1994, pp. 387-394
MRCISD(Q)/CASSCF calculations have been performed for the title dihydr
ides. The agreement with available experimental data is quite good for
the 1A1-B-3(1) singlet-triplet (S-T) energy gaps, as is agreement wit
h other calculations of similar quality. DFT calculations employing ba
sis sets of similar quality with non-local exchange and correlation co
rrections are two to three orders of magnitude faster than MRCI. DFT a
grees well with MRCI for the first and third rows, although the use of
different correlation functionals is required. Results in the second
row are only fair with either correlation functional.