Hellman-Feynman operator sampling in diffusion Monte Carlo calculations.
Hellman-Feynman operator sampling in diffusion Monte Carlo calculations.
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扩散蒙特卡罗计算中的 Hellman-Feynman 算子采样。
DOI：
10.1103/physrevlett.99.126406
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发表时间：
2007
影响因子：
8.6
通讯作者：
J. M. Pitarke
中科院分区：
文献类型：
--
作者：
R. Gaudoin;J. M. Pitarke
扩散蒙特卡罗（DMC）计算通常在固态和量子化学计算中产生高度精确的结果。然而，不与哈密尔顿算子交换的算子，一旦应用简单的校正，最多在底层试验波函数的误差中被正确地采样到二阶。这个误差与变分计算中能量的误差在同一数量级。受这些问题困扰的算子包括势能和密度。本文根据Hellman-Feynman定理，提出了一种对真实的空间中所有对角算子进行正确DMC采样的新方法。我们的方法很容易实现在任何标准的DMC代码。
Diffusion Monte Carlo (DMC) calculations typically yield highly accurate results in solid-state and quantum-chemical calculations. However, operators that do not commute with the Hamiltonian are at best sampled correctly up to second order in the error of the underlying trial wave function once simple corrections have been applied. This error is of the same order as that for the energy in variational calculations. Operators that suffer from these problems include potential energies and the density. This Letter presents a new method, based on the Hellman-Feynman theorem, for the correct DMC sampling of all operators diagonal in real space. Our method is easy to implement in any standard DMC code.