Emission of SH radicals in solid krypton: mixed quantum-classical molecular dynamics simulations

Direct simulations of the specific features in the A2Σ+(v′=0)→X2Π emission of SH radicals in solid krypton, namely, the appearance of two bands with different lifetimes, are carried out by using mixed quantum-classical molecular dynamics (MD). More evidence is provided to support the assignment of these two bands to different trapping sites of electronically excited SH in krypton, including estimates of the radiative lifetimes. The higher-energy emission with a shorter lifetime corresponds to a site with relatively free movement of SH(A) inside the lattice. The emission at longer wavelengths and with longer lifetime originates from a site where one of the matrix atoms is attached to the guest molecule forming a transient complex SH(A)·Kr inside the solvation shell.