Ab initio SCF CI study of the electronic spectra of nitroethylene

Abstract

Configuration interaction studies of ground, n→π* and π→π* electronically excited states are reported for nitroethylene in its ground-state equilibrium geometry. In case of the n→π* transitions, the two symmetry combinations of oxygen lone pair orbitals are found to give almost the same transition energies of 4·42 eV and 4·48 eV. These are in good agreement with the experimental transition energy of 4·20 eV. The calculated transition energy to the lowest π→π* excited ¹ A′ state of 5·48 eV is also in good agreement with the reported experimental value of 5·12 eV. Numerous other singlet states as well as the triplet states have also been calculated.