Relativistic Jahn-Teller effects in the photoelectron spectra of tetrahedral P_4, As_4, Sb_4, and Bi_4

摘要

The group-V tetrahedral cluster cations P_(4+), As 4+, Sb 4+, and Bi 4+ are known to exhibit exceptionally strong Jahn-Teller (JT) effects of electrostatic origin in their ~2E ground states and ~2T _2 excited states. It has been predicted that there exist, in addition, JT couplings of relativistic origin (arising from the spin-orbit (SO) operator) in ~2E and ~2T_2 states of tetrahedral systems, which should become relevant for the heavier elements. In the present work, the JT and SO couplings in the group-V tetramer cations have been analyzed with ab initio relativistic electronic structure calculations. The vibronic line spectra and the band shapes of the photoelectron spectra were simulated with time-dependent quantum wave-packet methods. The results provide insight into the interplay of electrostatic and relativistic JT couplings and SO splittings in the complex photoelectron spectra of these systems.