精确固定节面量子Monte Carlo差值法

Differential Accurate Fixed-node Quantum Monte Carlo Method

提出了精确固定节面量子MonteCarlo差值法,这个新算法能够在精确固定节面量子MonteCarlo方法的基础上直接计算两个体系之间的能量差,且使计算结果的统计误差达到10-5hartree数量级,获得电子相关能90%以上.我们把这个新算法应用于分子势能面的研究中,使用一个“刚性移动”模型,利用Jacobi变换使分子两个几何构型的能量计算具有很好的正相关性,因而能得到准确的能量差值,由此就可以得到精确的分子势能面.

A novel quantum Monte Carlo(QMC) differential approach was proposed, which can be used to directly compute the energy difference between two systems on the basis of accurate fixed-node QMC algorithm, allowing the statistical error in the order of 10(-5) hartree and the electron-correlation energy over 90% for the computation results. By using a 'rigid move' model and Jacobi transformation, a good positive correlation between energies of two configurations for a molecule was obtained, and thus the acquisition of accurate energy differences and molecules' potential energy surfaces for two investigated systems is feasible.