以第一原理密度泛函理論研究鈾和其他材料的晶格振動行為

Abstract

We used force-constant method to study the lattice dynamics of uranium. We performed the uranium phonon dispersion relations with scalar relativistic, on-site coulomb interaction, and spin-orbital coupling calculations. The force-constant method has given very good results for materials with strong covalent bonding (such as diamond) and cubic structures. We predict the structural phase transition of iron in high pressure from imaginary frequencies of phonon dispersions. For uranium, we get better results in [110] and [001] direction in phonon dispersions calculation with on-site coulomb interaction. In our calculations, we used the Vienna ab-initio simulation package (VASP) based on density-functional theory (DFT) with generalized gradient approximation (GGA) plus projector-augmented wave (PAW) method.