Ab initio simulation of the vibrationally resolved photoelectron spectrum of Si3-

J Chem Phys. 2007 Feb 21;126(7):074305. doi: 10.1063/1.2472329.

Abstract

Electron photodetachment spectra provide a wealth of information about the electronic and vibrational level structures of neutral molecules that form stable anions. Experiments carried out for the smallest polyatomic silicon cluster anion (Si3-+hupsilon-->Si3*+e-) show vibrational progressions in six observed electronic bands (X-E) of the neutral species. The authors have performed ab initio calculations using the MRCI+D/aug-cc-pVQZ level for the corresponding electronic states followed by variational calculations of the vibronic levels associated with these adiabatic potential energy surfaces. In contrast to previous approaches, the authors treat the nonadiabatic dynamics on the potential energy surfaces, which allows for a vastly improved reproduction of the experimental level structure and a corrected assignment for band A.