论文标题
辅助场量子蒙特卡洛的最新发展用于真实材料
Some Recent Developments in Auxiliary-Field Quantum Monte Carlo for Real Materials
论文作者
论文摘要
辅助场量子蒙特卡洛（AFQMC）方法是一种通用数值方法，用于相关的多电子系统，它越来越多地应用于晶格模型，原子，分子和固体中。在这里，我们介绍了专门用于真实材料的方法的理论和算法，并提出了最近的一些发展。我们对AFQMC的关键步骤进行系统的说明，并密切跟踪我们正在开发的现代软件库的框架。详细讨论了蒙特卡洛汉密尔顿（Monte Carlo Hamiltonian），投影到基态，对两体操作员进行采样，无相相近似和测量基态性能。描述了针对多确定试验波函数的高级实现，该功能大大加速了算法并降低了内存成本。我们提出了对真实材料的自一致性约束，并通过将AFQMC计算与有效的独立电子计算或通过计算的一体密度矩阵的天然轨道结合，讨论了两种口味以实现其实现。
The auxiliary-field quantum Monte Carlo (AFQMC) method is a general numerical method for correlated many-electron systems, which is being increasingly applied in lattice models, atoms, molecules, and solids. Here we introduce the theory and algorithm of the method specialized for real materials, and present several recent developments. We give a systematic exposition of the key steps of AFQMC, closely tracking the framework of a modern software library we are developing. The building of a Monte Carlo Hamiltonian, projecting to the ground state, sampling two-body operators, phaseless approximation, and measuring ground state properties are discussed in details. An advanced implementation for multi-determinant trial wave functions is described which dramatically speeds up the algorithm and reduces the memory cost. We propose a self-consistent constraint for real materials, and discuss two flavors for its realization, either by coupling the AFQMC calculation to an effective independent-electron calculation, or via the natural orbitals of the computed one-body density matrix.
