剩余函数量子Monte Carlo方法

为量子Ｍｏｎｔｅ Ｃａｒｌｏ方法提出一条新途径－剩余函数法，引入了Ｓｃｈｒｏｅｄｉｎｇｅｒ方程剩余函数的概念，利用剩余函数将一种新的有明显物理意义的试探函数应用到量子Ｍｏｎｔｅ Ｃａｒｌｏ过程中，这种试探函数是通过一种迭进式的方式确定的，它不需要在Ｍｏｎｔｅ Ｃａｒｌｏ过程中优化参数。文中我们将给出这种试探函数的具体形式，证明由这种试探函数求出的能量期望值收敛于体系真实的能量值；文中还给出这种试探

Surplus Function Quantum Monte Carlo Approach

A concept of surplus function for Schrodinger equation is put forward. A novel quantum Monte Carlo approach entitled surplus function method is suggested with use of a novel trial function of significant physical meaning which is based on the proposed surplus function. The trial function is of an iteration-type and suffers no time-consuming parameter optimum in a quantum Monte Carlo process. It is theoretically proved that the energy expectation value obtained from the proposed trial function converges to the exact energy value of the system inveshgated. In addition,computation formulas and procedures for energy expectation value are presented. Calculations for several molecules indicate that the energy expectation value obtained from the trial function does converge to the exact energy value of the investigated system and the converging rate is very fast as generally only 4-5 iterations achieves over 90% correlation energy. To our knowledge, both the calculating precision and converging rate of the trial function proposed are the highest one in the quantum Monte Carlo approach at present time.