Ab initio study of excited electronic states and vibronic spectra of phenyl radical

Geometries, vibrational frequencies, excitation energies, and vibronic spectra of seven excited states of C6H5 have been studied by multireference ab initio calculations. For the 1(2)B(1), 1(2)B(2), 2(2)B(2), and 2(2)B(1) states the most intense vibronic peaks are calculated at 17952, 37744, 43380, and 43251 cm(-1), respectively, and for 1(2)A(2), 2(2)A(1), and 3(2)A(1) upper estimates for adiabatic excitation energies are 22176, 30988, and 42543 cm(-1). We have assigned the 530-440 nm band in the absorption spectra to 1(2)B(1) with possible contribution from 1(2)A(2), the 265-230 mn band to 1(2)B(2) and 3(2)A(2), and intense peaks starting from similar to212 nm to 2(2)B(1) and 2(2)B(2). (C) 2002 Elsevier Science B.V. All rights reserved.