First-principles molecular dynamics study on simple cubic calcium: comparison with simple cubic phosphorus

Abstract

In this paper, the dynamical behavior of simple cubic (sc) calcium is investigated by first-principles molecular dynamics (MD) simulation at 40 GPa and 300 K and is compared with that of sc phosphorus. As a result, we found that calcium shows larger structural fluctuation through the MD simulation than phosphorus but the dynamical structures of calcium and phosphorus both become the sc structure. On the other hand, performing a structural optimization in the course of the MD simulation, we obtained that phosphorus and calcium take the sc structure and a distorted sc structure, respectively, and the static structures of calcium and phosphorus are inconsistent with each other. These results indicate that sc calcium is stabilized by thermal effects, which is quite different from the stabilization process of sc phosphorus.

Keywords:

• first-principles calculation
• molecular dynamics
• calcium
• phosphorus
• simple cubic

Acknowledgements

This research is supported by the Japan Society for the Promotion of Science (JSPS) through its ‘Funding Program for Next Generation World-Leading Researchers (NEXT Program)’ No. GR068 and ‘KAKENHI’ No. 22340106.