Ab initio calculations of excited states of vinyl bromide

Abstract The equilibrium geometries and harmonic vibrational frequencies of the singlet (π,π ∗ ), (π,3s), (π,σ ∗ ), (π,3p x ), and (π,3p y ) excited states of vinyl bromide have been calculated using the state-averaged complete active space self-consistent field method with the 6-311++G(d,p) basis set and an active space of four electrons distributed in 13 orbitals. Both adiabatic and vertical excitation energies of the excited states of vinyl bromide have been computed using the multireference configuration interaction method. Franck–Condon factors have been evaluated using a new formula to simulate the absorption spectra of vinyl bromide and the agreement with the experiment is satisfactory.