从第一原理结合能曲线反演得到同种及异种原子间相互作用势,并以此对Ni_3Al中合金元素的择优替位行为进行了系统地研究。考虑长程作用,并利用对多个弛豫样本求平均的方法,对不同含量合金下的择优替位行为进行了定量计算。以不同组态下结合能的相对大小作为合金元素选择性替位的判据,计算结果与实验符合良好。对实验上尚不存在的一些合金元素的替位行为及表面、界面上部分元素的择优替位行为给出了理论预言。 The potential of the same species and heterogeneous atoms was inversed by the first-principle binding energy curve, and the preferred substitution behavior of alloying elements in Ni_3Al was studied systematically. Considering the long-range effect, and using the method of averaging multiple relaxation samples, the quantitative alternative displacement behaviors under different alloy contents were calculated. The relative size of the binding energy under different configurations is taken as the criterion for the selective replacement of alloying elements. The calculated results are in good agreement with the experimental results. The substitution behavior of some alloying elements which did not exist experimentally and the preferential substitution behavior of some elements on the surface and interface were given.