金属铜的晶体结构与热力学性质的第一性原理计算

基于第一性原理,利用密度泛函理论(DFT)和密度泛函的微扰理论(DFPT),以及广义梯度近似(GGA),研究了过渡金属Cu的晶体结构、能量、电子能带和态密度、声子的能带结构和态密度,以及其在298.15 K下的热容,体积模量,格林艾森参数和体胀系数等热力学函数并与实验值作了对比.通过分析Cu的晶格几何与能量之间的关系,讨论了金属Cu的固-液相变与晶格声子振动能量之间可能的内在联系,首次提出直接得到Cu熔化温度T_m的静力学方法,研究了熔化温度与压强的关系.计算结果与实验值符合较好,明显优于分子动力学模拟的结果.

First-principle calculation for the lattice and thermodynamics of copper

Based on the first principle, using density functional theory (DFT), density functional perturbation theory (DFPT) and generalized gradient approximation (GGA) with pseudo-potential method, the lattices, energies, electronic bands and density of states, phonon bands and density of states for the transition metal copper .as well as its heat capacity, bulk modulus, Grüneisen parameter, coefficient of thermal expansion in 298.15K are calculated. The relationship between the energy and lattice of copper is analyzed. The nature of solid-liquid phase changes with the vibration of phonon energy is discussed. A static method to derive the melting temperature for copper is the first suggested. The relationship of melting temperature with pressure is researched. Our calculation of melting temperature is more acceptable than the result with molecular dynamic simulation, compared with the experimental values.