SCF scheme for excited states and analysis of the orbital relaxation effect for H2O and FNO

Abstract An SCF scheme for excited states of closed‐shell systems based on the direct minimization technique is discussed. The utility of the scheme is tested for several excited states of H2O. The contribution of various tyeps of optimization of orbitals occupied in the excited state is discussed using the example of H2 O and FNO. It was found that relaxation of doubly occupied orbitals always gives a significnat contribution to the lowering of the excited state energy in the SCF process. Unexpectedly, on the other hand, optimization of the excited orbital in many cases gave negligible results.