Simulations of the absorption band of the D-state of Hg2 in rare gas matrices

We present molecular dynamics simulations of the absorption spectra of the Hg2 molecule in solid neon, argon, and xenon. The simulations were performed using classical molecular dynamics (MD) and a diatomic-in-molecules (DIM) treatment of the mixing of the different states of Hg2 induced by the environment. The experimental relative shifts of the X0g+–D1u transition band are qualitatively well reproduced. The origin of these shifts is identified as the result of two combined factors: the effect of the host onto the Hg–Hg equilibrium distances and the different interaction of each matrix with the Hg2 electronic states.