A potential curve and spectroscopic constants of ${\mathrm{Hg}}_2$ were calculated using multireference single- and double-excitations configuration interaction calculations, where $5d$ and $6s$ electrons were correlated. The calculated constants were consistent with experimental data. Using the potential curves of ${\mathrm{Hg}}_2,$ we performed molecular-dynamics (MD) calculations to identify the melting point of mercury. A characteristic feature of liquid metal, cooperative motion, was observed in the MD calculations. On the other hand, MD calculations using a Lennard-Jones potential gave the cooperative motion only in very short time intervals $(t<\mathrm{}0.5\mathrm{}\mathrm{ps}).\mathrm{}$

• Received 2 September 1997

DOI:https://doi.org/10.1103/PhysRevB.57.914