特征原子势能配分函数
(1. 中南大学 材料科学与研究工程学院，长沙 410083；
2. 中南大学 粉末冶金国家重点实验室，长沙 410083；
3. 中南大学 物理科学与技术学院，长沙 410083；
4. 湘潭大学 机械工程学院，湘潭 411105；
5. 中南大学 化学化工学院，长沙 410083)
摘 要: 介绍以第一原理合金电子理论为基础的系统合金科学(FP-SSA)框架中Au3Cu型有序合金的特征原子势能(CAPE)配分函数。主要创新内容如下：以基本原子团 和 序列的中心特征原子 和 为结构单元序列，替代原子对和原子团，建立了合金相的特征原子排列模型；以配位原子团 对作用于特征原子势场影响的方式替代原子对能量相互作用和原子团能量相互作用方式，以特征原子势能能级代替原子对能级和原子团能级，建立了合金相的“特征原子势能相加定律”，计算合金相及其组元的平均势能；在特征原子排列的简并因数与特征原子势能能级一致的条件下建立CAPE配分函数和计算组态熵。此函数揭示了当今流行的固溶体理论的不足之处，为建立特征Gibbs能配分函数奠定了基础。
关键字: Au3Cu型有序合金；第一原理；系统合金科学；特征原子；势能；配分函数
Au3Cu type ordered alloys in FP-SSA framework
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. School of Physical Science and Technique, Central South University, Changsha 410083, China;
4. College of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China;
5. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:The innovations of the characteristic atom potential energy (CAPE) partition function of Au3Cu type ordered alloys in the systematic science of alloys (SSA) based on first principle (FP)-electronic theory of alloys are concluded in the three aspects: the characteristic atoms and at centers of the basic clusters and are taken as structural unit sequences, which are used to replace the atomic pairs and atomic clusters; the potential energy levels and result from the influence of coordinative cluster on the characteristic atoms, which are used to replace pairwise interaction energies and cluster interaction energies; the additive law of potential energies of characteristic atoms is established; the average potential energies of alloy phases and their components are calculated; the unity between the degeneracy factors of arrangements and the potential energy levels of characteristic atoms is taken into account for establishing CAPE-partition function and calculating configurational entropy. It reveals some shortcomings of the currently used solution theories and can lay the foundation for establishing Gibbs energy partition function.
Key words: Au3Cu-type ordered alloys; the first principle; systematic science of alloys; characteristic atom; potential energy; partition function
