摘要
势函数对分子动力学计算的准确性和可靠性具有决定作用,如何获得精确的势函数一直是最受人们关注的问题之一。为了构建Fe-Mn原子间的势函数,利用基于密度泛函理论的第一性原理方法分别计算了BCC-Fe,BCC-Mn及L_(10)-FeMn体系的结合能曲线,而后根据Chen-Mobius晶格反演法得到了FCC-Fe和FCC-Mn的晶格反演势。然后计算出Fe-Fe原子和Mn-Mn原子间按L_(10)结构堆垛的结合能,进而求出Fe-Mn原子间的结合能,再利用Chen-Mobius晶格反演法,获得Fe-Mn原子间的晶格反演势,最后选择Morse势函数进行拟合。利用构建的Fe-Mn势函数进行了L_(10)-FeMn体系结合能计算,与第一性原理计算的结果对比,表明构建的Fe-Mn势函数满足自洽性。最后利用所得势函数进行了弹性模量、杨氏模量计算,与试验数据对比基本吻合,表明势函数具有有效性。
The interatomic potential plays a decisive role in the accuracy and reliability of molecular dynamics(MD)calculation.How to obtain accurate interatomic potential has been one of the most concerned problems.In order to found the interatomic potential between Fe and Mn atoms,the cohesive energy curves of BCC-Fe,BCC-Mn and L_(10)-FeMn are calculated via the first-principles method based on density functional theory,and the lattice inversion potentials of BCC-Fe and BCC-Mn were founded according to the Chen-Mobius lattice inversion method.Then the cohesive energy of Fe atom and Mn atom in L_(10) structure is calculated according to their stacking structure,then the cohesive energy of Fe atom and Mn atom is calculated.The lattice inversion potential of Fe-Mn atom is obtained via Chen-Mobius lattice inversion method,and the Morse potential function is selected for fitting.Using the Fe-Mn potential function to calculate the cohesive energy of the Fe-Mn system,compared with the results of the first-principle calculation,it shows that the Fe and Mn potential function satisfies the self-consistency.Finally,the bulk modulus and Young's modulus are calculated by using the potential function,which is basically consistent with the experimental data,indicating that the potential function is effective.
作者
李宁
张兴广
吴冰洁
李雪洁
杨龙龙
孙琨
张猛
LI Ning;ZHANG Xingguang;WU Bingjie;LI Xuejie;YANG Longlong;SUN Kun;ZHANG Meng(Key Laboratory of Nuclear Reactor System Design Technology,China Nuclear Power Research and Design Institute,Chengdu 610014,China;State Key Laboratory for Mechanical Behavior of Materials,Xi′an Jiaotong University,Xi′an 710049,China)
出处
《有色金属工程》
CAS
北大核心
2021年第6期24-28,共5页
Nonferrous Metals Engineering
基金
国家自然科学基金资助项目(52075417,51475359)。
