发表机构
Linköping University（林雪平大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究开发了一种通用算法，可生成无代数耦合的最少应变构型集，用于从第一性原理应力-应变计算中提取二阶弹性常数，其应变集适用于230个晶体空间群，且效率和准确性优于现有方法。
AI 中文摘要
我们开发了一种通用算法，用于构建从第一性原理应力-应变计算中提取二阶弹性常数所需的最少应变构型数量，且待提取的弹性常数之间无代数耦合。该方法基于对称性约化弹性刚度矩阵的稀疏结构（由辅助二元矩阵表示）运行，通过算法生成可容许的应变模式，而非为单个晶体对称性规定单独的应变集。每个独立弹性常数可从单一应力分量中获取，同一变形产生的额外应力关系则提供内部一致性校验。由于六维应变空间仅包含2^6-1=63种非空应变模式，因此可对所考虑的每种弹性对称类型精确验证所得应变集的最小性。该构建在现有高效应变集为最小的情况下可复现这些集，而对于先前制表方案需要额外构型的对称类，则能生成改进的应变集。由于该公式基于应力-应变导数，因此也可通过一致采样的系综平均热力学应力，轻松扩展至有限温度情况。针对涵盖230个晶体空间群的所有弹性对称类型推导了明确的应变集，并将其准确性和计算效率与现有方法进行了基准测试。
英文摘要
We have developed a general algorithm for constructing the minimum number of strain configurations required to extract second-order elastic constants from first-principles stress-strain calculations without algebraic coupling between the constants targeted for extraction. The method operates on the sparsity structure of the symmetry-reduced elastic stiffness matrix, represented by an auxiliary binary matrix, and generates admissible strain patterns algorithmically rather than prescribing separate strain sets for individual crystal symmetries. Each independent elastic constant is obtained from a single stress component, while additional stress relations generated by the same deformation provide internal consistency checks. Because the six-dimensional strain space contains only 2^6-1=63 non-empty strain patterns, the minimality of the resulting sets can be verified exactly for every elastic-symmetry type considered. The construction reproduces established high-efficiency strain sets in cases where they are minimal and yields improved sets for symmetry classes in which previously tabulated schemes require additional configurations. Because the formulation is based on stress-strain derivatives, it can also be readily extended to finite temperatures using consistently sampled ensemble-averaged thermodynamic stresses. Explicit strain sets are derived for all elastic-symmetry types spanning the 230 crystallographic space groups, and their accuracy and computational efficiency are benchmarked against established approaches.
