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基于马儿可夫链理论和Bragg-Williams型方程,建立了描述反位缺陷占位几率的基本方程和转移几率;推导出了平衡时空位与反位缺陷浓度的表达式。利用所建模型结合第一性原理平面波赝势法系统研究了NiAl中各种点缺陷,从定量计算和电子结构角度论证了平衡状态下,在Ni:Al=1附近,Ni和Al原子的占位服从Fermi-Dirac统计,并且当温度从800增加到1300K时,NiAl几率比AlNi几率大106～109倍,反位缺陷以NiAl为主。VNi浓度比AlNi浓度大105～107倍、而NiAl浓度比VAl浓度大106～1010倍。对于同一原子而言,NiAl比VNi稳定,AlNi比VAl稳定。
Based on the Markov chain theory and the Bragg-Williams equation, the basic equations describing the occupancy probability of transversal defects and the transfer probability are established. The expression of equilibrium concentration of space time and transversal defect is deduced. The model and the first-principle plane-wave pseudopotential method were used to systematically study the various point defects in NiAl. From the aspects of quantitative calculation and electronic structure, it is demonstrated that the Ni and Al atoms account for about Ni: Al = 1 Bit obeys Fermi-Dirac statistics, and when the temperature increases from 800 to 1300K, the probability of NiAl is 106 ~ 109 times greater than that of AlNi, and NiAl is the main reverse transversal defect. The VNi concentration is 105 to 107 times larger than the AlNi concentration, while the NiAl concentration is 106 to 1010 times larger than the VAl concentration. For the same atom, NiAl is more stable than VNi and AlNi is more stable than VAl.