Kutepov A L
Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, United States of America.
J Phys Condens Matter. 2021 May 11;33(23). doi: 10.1088/1361-648X/abf384.
The atomic forces formulation based on the Dirac-Kohn-Sham equation and the flexible (APW + lo/LAPW) + LO basis set is presented. The formulation was implemented in the code FlapwMBPT and allows a user to easily switch between different basis functions of the augmentation type (APW or LAPW) and between different kind of local orbitals. Similar to the work (2015035105), the implementation takes into account small discontinuities of the wave functions, density, and potential at the muffin-tin sphere boundaries. Applications to the materials with strong relativistic effects, such as-uranium, PuCoGa, and FePt, demonstrate robustness of the method. The comparison of the calculated forces with the ones obtained by numerical differentiation of electronic free energy shows close agreement with deviations about 0.1% or less.
提出了基于狄拉克 - 科恩 - 沙姆方程和灵活的（全势缀加平面波+局域轨道/线性缀加平面波）+局域轨道基组的原子力公式。该公式已在代码FlapwMBPT中实现，允许用户轻松地在不同类型的增强型基函数（全势缀加平面波或线性缀加平面波）之间以及不同类型的局域轨道之间进行切换。与文献（2015035105）的工作类似，该实现考虑了波函数、密度和势在 muffin-tin 球边界处的小间断。对具有强相对论效应的材料（如铀、PuCoGa 和 FePt）的应用证明了该方法的稳健性。将计算得到的力与通过电子自由能数值微分得到的力进行比较，结果显示偏差约为0.1%或更小，二者吻合度很高。
