Me. Casida et al., EXCITED-STATE POTENTIAL-ENERGY CURVES FROM TIME-DEPENDENT DENSITY-FUNCTIONAL THEORY - A CROSS-SECTION OF FORMALDEHYDES (1)A(1) MANIFOLD, International journal of quantum chemistry, 70(4-5), 1998, pp. 933-941
This work reports the first density-functional theory (DFT) treatment
of excited-state potential energy surfaces exhibiting avoided crossing
s. Time-dependent DET (TD-DFT) results, using a recently proposed asym
ptotically corrected local density approximation functional, are compa
red with multireference doubles configuration interaction (MRD-CI) res
ults for the (1)A(1) manifold of the CO stretching curves of planar fo
rmaldehyde. TD-DFT is found to reproduce the qualitative features esse
ntial for understanding the spectroscopy of this manifold, specificall
y the strong mixing of the (1)(pi, pi) With Rydberg transitions and t
he resultant avoided crossings. (C) 1998 John Wiley & Sons, Inc.