Time-dependent quantum simulations of FH2− photoelectron spectra on new ab initio potential energy surfaces for the anionic and the neutral species

The photoelectron spectra (`transition state spectraʹ) of FH2− generated experimentally from para- and normal-H2 are simulated on new ab initio potential energy surfaces using standard quantum time-dependent wavepacket techniques, and compared directly to experimental spectra. Agreement between theory and experiment is improved compared to earlier simulations. Two factors are shown to contribute to this success: (1) the anharmonicity of the exact vibrational wavefunctions on a new ab initio surface for the anion and (2) a new spin–orbit correction applied to the ab initio surface for neutral FH2. Possible reasons for the small remaining discrepancies are investigated and discussed. Finally, predictions are given for spectra obtainable in future high-resolution experiments of this system.