Nonharmonic vibrational effects in HgClOH: An MP2 Born–Oppenheimer molecular dynamics study

Abstract

AbstractWe report a Born–Oppenheimer molecular dynamics study of HgClOH to address the nonharmonic (NH) effects which are important in the development of classical interaction potentials. The electronic structure calculations were performed with the second order Möller–Plesset version of perturbation theory. For the Hg and Cl atoms, the Stuttgart–Dresden relativistic effective core potentials were used with extended‐optimized valence basis, while for O and H the aug‐cc‐pVnZ (n = D,T,Q) basis sets were used. Dynamic effects introduce non‐negligible changes to the equilibrium HgO distance and the ClHgO angle which shows rather large (but still harmonic) variations. The largest NH effects appear for the in‐molecular‐plane HOHg bending and the OH stretching modes. The results for the isolated molecule are relevant to compare the geometrical parameters with the water‐solvated species, both through cluster models or through condensed liquid phase studies. © 2012 Wiley Periodicals, Inc.