Electronic structure calculations for large planar molecules by SCF-scattered wave method

Abstract

Electronic structure calculations using the SCF-scattered wave program of Johnson and Smith for the molecules carbazole, fluorenone, dinitrofluorenone, and trinitrofluorenone are reported. A qualitative description of the lowest excited states of these molecules is presented and a brief review of the theory underlying the calculations is given. Our calculations predict that the lowest excitation in carbazole should be polarized along the short molecular axis and in fluorenone along the long molecular axis. Polarized light absorption experiments should then provide an excellent check on the validity of these calculations. It is also shown that the lowest excitation in carbazole, fluorenone, and dinitrofluorenone should be a π→T*transition whereas in trinitrofluorenone it is suspected to be an n → pi;*transition. Comparison with minimal basis LCAO Hartree-Fock calculations and experiments is made where possible.