Ab initio calculations of vibronic spectra for indole

Abstract

Detailed vibronic fluorescence spectra from the 1L b and 1L a state origins of indole are computed from the geometry differences and ground state normal modes determined by GAUSSIAN 92 and a program to calculate Franck-Condon factors. The combination of using CIS/3-21G and HF/3-21G basis sets for excited and ground state geometries and MP2/6-31G ∗ for the ground state vibrational modes captures many subtle details seen in the experimental 1L b fluorescence.