A new method of calculation of Franck-Condon factors which includes allowance for anharmonicity and the Duschinsky effect: Simulation of the He I photoelectron spectrum of ClO 2

摘要: A new method of Franck-Condon (FC) factor calculation for nonlinear polyatomics, which includes anharmonicity and Duschinsky rotation, is reported. Watson's Hamiltonian employed in this with multidimensional ab initio potential energy functions. The anharmonic vibrational wave functions are expressed as linear combinations the products harmonic oscillator effect, arises from rotation normal modes two electronic states involved transition, formulated Cartesian coordinates, was done previously an earlier FC model. This applied to simulation bands He I photoelectron (PE) spectrum ClO2. For first band, model shown be inadequate but gave a much-improved agreement observed spectrum. experimentally derived geometry (X) over tilde (1)A(1) state ClO2+ obtained, time, via iterative analysis procedure {R(Cl-O)=1.414 +/- 0.002 Angstrom, angle O-Cl-O=121.8 0.1 degrees}. heavily overlapped second PE band ClO2, corresponding ionization five cationic states, simulated using code. main features experimental were adequately accounted spectral reported here supports one sets published assignments based on multireference configuration interaction (MRCI) calculations. In addition, aid envelopes, set adiabatic (and vertical) energies all more reliable than reported, has been derived. led also reanalysis photoabsorption