论文标题
基于图的量子响应理论和阴影出生 - 启动分子动力学
Graph-based Quantum Response Theory and Shadow Born-Oppenheimer Molecular Dynamics
论文作者
论文摘要
用于量子力学分子动力学模拟的基于图的线性缩放电子结构理论适用于扩展的拉格朗日式Born-Oppenheimer分子动力学的最新阴影电势公式，包括分数分子 - 轨道占用数量，可以实现具有稳定的具有稳定的复杂化学系统的模拟，并具有稳定的模拟具有不稳定电荷溶液的敏感化学化学系统。提出的公式包括预处理的Krylov子空间近似，以整合扩展的电子自由度，这需要对具有分数职业数量的电子状态进行量子响应计算。对于响应计算，我们引入了基于图的规范量子扰动理论，该理论可以以与未扰动的基态的基于图基的电子结构计算相同的自然平行性和线性缩放复杂性进行。所提出的技术特别适合半经验电子结构理论，并且使用自洽的电荷密度密度功能紧密结合（SCC-DFTB）理论证明了这些方法，既可以加速自洽场计算，又用于量子分子动力学模拟。基于图的技术与半经验理论相结合，可以对大型复杂的化学系统（包括成千上万的原子）进行稳定的模拟。
Graph-based linear scaling electronic structure theory for quantum-mechanical molecular dynamics simulations is adapted to the most recent shadow potential formulations of extended Lagrangian Born-Oppenheimer molecular dynamics, including fractional molecular-orbital occupation numbers, which enables stable simulations of sensitive complex chemical systems with unsteady charge solutions. The proposed formulation includes a preconditioned Krylov subspace approximation for the integration of the extended electronic degrees of freedom, which requires quantum response calculations for electronic states with fractional occupation numbers. For the response calculations we introduce a graph-based canonical quantum perturbation theory that can be performed with the same natural parallelism and linear scaling complexity as the graph-based electronic structure calculations for the unperturbed ground state. The proposed techniques are particularly well-suited for semi-empirical electronic structure theory and the methods are demonstrated using self-consistent charge density-functional tight-binding (SCC-DFTB) theory, both for the acceleration of self-consistent field calculations and for quantum molecular dynamics simulations. The graph-based techniques combined with the semi-empirical theory enable stable simulations of large, complex chemical systems, including tens-of-thousands of atoms.
