We have performed coexistence phase molecular dynamics (MD) simulations to investigate the melting curve of tantalum over a wide range of pressures. To ensure faithful MD simulations, three types of potentials, including the extended Finnis-Sinclair (EFS) potential, the long-range empirical potential (LREP), and the force-matching (FM) potential, are fully tested. Through a series of tests, such as equation of states, thermal expansion, and other thermodynamic properties for liquid Ta, we have found that the EFS potential is the reliable potential for simulating both solid and liquid Ta. The EFS potential can also produce a satisfying melting curve, consistent well with both experiments of ambient pressure and shock melting at high pressure. However, the other two melting curves from the LREP and the FM potential have not so satisfying agreement with shocking melting at high pressure. Hence we recommend that the EFS should be the reliable potential for simulating melting properties of Ta as well as other properties of solid and liquid Ta.

• Received 7 August 2007

DOI:https://doi.org/10.1103/PhysRevB.77.024103