Temperature effects on the absorption spectra of Li in solid H-2 under high pressure: A path integral Monte Carlo study

The temperature dependence (5-45 K) of the absorption spectra of a Li atom doped in solid hydrogen at P = 1.2 GPa is investigated using the path integ ral Monte Carlo (PIMC) method vith a constant pressure ensemble. Higher tem perature in our research range does not cause rearrangement of the trapping site structures. The significantly broadening and spreading of the three c omponent absorptions with increasing temperature are observed. For the trap ping site structures belonging to lower symmetry point groups, the singlet to doublet splitting decreases as temperature gets larger. An insight on th e temperature-induced behaviors of the Li absorption spectrum in the doped system has been made by using the simulated results.