A CASSCF STUDY OF THE S-0 AND S-1 STATES OF PHENOL

Different basis sets and active spaces have been employed to determine the geometries and vibrational frequencies of phenol in its electroni c ground and first excited stale at the CASSCF level of theory. Good a greement with experimentally determined rotational constants was achie ved using Dunning's correlation consistent cc-pVDZ basis set. The elec tronic origin of the S-1 <-- S-0 excitation has been calculated with a n accuracy of 0.1 eV considering zero-point energy corrections for bot h the S-0 and S-1 states. Additionally, S-1 state frequencies were cal culated al the CIS/cc-pVDZ level of theory.