Structure of liquid bismuth calculated from pseudo-potentials and molecular dynamics

Abstract

Earlier calculations on liquid bismuth have been done by using five conduction electrons. However, this metal presents, in the liquid state, a gap in its electronic density of states that clearly separates the s and the p bands. Thus, the number of free electrons to be considered is affected by the existence of the gap. Previous calculations on the structure of liquid bismuth with five conduction electrons did not give satisfactory results. Molecular dynamics calculations using an effective potential derived from the empty core potential (ECP) and from the local optimised model potential (OMP) are presented and compared with the results obtained with three (p) and five (s + p) conduction electrons. The results, obtained for the first time to our knowledge for liquid bismuth at different temperatures, with three conduction electrons and OMP are in very good agreement with the Waseda structural experimental data. This approach using three conduction electrons is confirmed by resistivity calculations using the t-matrix model.

Keywords:

• liquid metal
• bismuth
• atomic structure
• pseudo-potentials
• molecular dynamics