Exploring the structure and photodissociation mechanism of the electronic states of monochlorogermylene including the spin-orbit-coupling.

The electronic states of monochlorogermene (HGeCl) are computed by using the explicitly correlated internally contracted multireference configuration interaction (icMRCI-F12) method with Davidson correction. A total of 23 spin-free states with energy up to 9.4 eV as well as 55 spin-orbit coupled states generated by these spin-free states after considering the spin-orbit coupling (SOC) effect are investigated. The geometries and harmonic vibrational frequencies of the lowest electronic states are calculated, and the spectroscopic constants, oscillator strength, vertical transition energy and potential energy curves (PECs) of the spin-free states and spin-coupled states are presented. Based on the calculation of the electronic states, the photodissociation dynamics in the ultraviolet region is discussed. Our studies will shed light on the electronic structure and decomposition processes of HGeCl radicals.