Calculation of ground- and excited-state potential energy curves for the Hg 2 molecule in a pseudopotential approach

Abstract

Potential energy curves for electronic states of the Hg 2 dimer are calculated using the SCF and MRCI scheme for the four valence electrons of the system, with the core electrons represented by ab initio quasirelativistic energy adjusted pseudopotentials. Computations are performed for the molecular states that dissociate to the Hg( 1S)+Hg( 1S, 3P, 1P, 7s 3S, 7s 1S, 7p 3P, 7p 1P) asymptotes. The calculated potential curves are split into spin-orbit components in a semiempirical manner following the “atoms-in-molecules” model. Comparison of the derived potentials with known experimental data shows overall good agreement between theory and experiment, although the theoretical potentials are somewhat too shallow.