论文标题
开发基于QSGW和DFT计算的数据驱动的SPD紧密结合模型 - 包括有关高阶弹性常数的信息
Development of data-driven spd tight-binding models of Fe -- parameterisation based on QSGW and DFT calculations including information about higher-order elastic constants
论文作者
论文摘要
量子力学(QM)模拟得益于其预测能力,可以为缺陷的性质和动态提供重要的见解,例如空位,错位和晶界。在开发可靠,廉价和环保合金的背景下,这些考虑是必不可少的。但是,尽管计算机性能取得了重大进展,但缺陷的QM模拟仍使用AB-Initio/非参数方法非常耗时。两中心的Slater-Koster(SK)紧密结合(TB)模型可以实现明显的计算效率,并提供可解释的电子结构图片。在某些情况下,这使TB成为基于电子结构的抽象(例如嵌入原子模型)的模型的引人注目的替代方案。实施SK方法的最大挑战是估计用于构建汉密尔顿矩阵的最佳和可转移参数。在本文中,我们将遵循调整参数的经典方法,以便重新创建可以使用AB-Initio或非参数方法来重新创建属性的经典方法,从而介绍开发数据驱动框架的结果。不同的特征包括合并来自QSGW(准粒子自洽的GW近似)计算的数据,以及考虑高阶弹性常数。此外,我们提供了许多出版物(包括设计阶段)中省略的优化过程的描述。我们还采用现代优化技术,使我们能够最大程度地减少对参数空间的约束。总而言之,本文在解决相关的挑战和优势的同时介绍了对半经验方法的一些方法论改进。
Quantum-mechanical (QM) simulations, thanks to their predictive power, can provide significant insights into the nature and dynamics of defects such as vacancies, dislocations and grain boundaries. These considerations are essential in the context of the development of reliable, inexpensive and environmentally friendly alloys. However, despite significant progress in computer performance, QM simulations of defects are still extremely time-consuming with ab-initio/non-parametric methods. The two-centre Slater-Koster (SK) tight-binding (TB) models can achieve significant computational efficiency and provide an interpretable picture of the electronic structure. In some cases, this makes TB a compelling alternative to models based on abstraction of the electronic structure, such as the embedded atom model. The biggest challenge in the implementation of the SK method is the estimation of the optimal and transferable parameters that are used to construct the Hamiltonian matrix. In this paper, we will present results of the development of a data-driven framework, following the classical approach of adjusting parameters in order to recreate properties that can be measured or estimated using ab-initio or non-parametric methods. Distinct features include incorporation of data from QSGW (quasi-particle self-consistent GW approximation) calculations, as well as consideration of higher-order elastic constants. Furthermore, we provide a description of the optimisation procedure, omitted in many publications, including the design stage. We also apply modern optimisation techniques that allow us to minimise constraints on the parameter space. In summary, this paper introduces some methodological improvements to the semi-empirical approach while addressing associated challenges and advantages.