Quantum Chemistry by Random Walk

詹姆斯教授B。安德森得到了 理论与计算化学课程探索 研究绿色函数的量子蒙特卡罗方法 化学系统。安德森教授一直在大量使用 并行计算机，如CM-2连接机， 执行绿色函数蒙特卡罗计算简单 三原子系统，如氢原子之间的反应 和氢分子。 在他最近的计算中 完成了四体氢分子的计算，他能够 在65 K处理器上实现1.5 gigaflop的持续速度 CM-2计算机，总精度为0.006千卡/摩尔。 安德森将研究氢的反应表面 使用相同的方法进行交换反应 精度预期优于0.01千卡/摩尔 整个势能面。 他还希望研究 氟原子加氢的势能面 分子反应 其他有待研究的系统包括 半导体微晶中的激子，扩展分子 由小的多原子分子和团簇组成的系统 氦原子。 %%% 本项目中将进行的计算如下： 重要的是，它们形成了一个精确的基准， 可以测试其它电子结构理论模型。

Professor James B. Anderson is supported by a grant from the Theoretical and Computational Chemistry Program to explore Green's Function Quantum Monte Carlo techniques for studying chemical systems. Professor Anderson has been using massively parallel computers such as the CM-2 connection machine to perform Green's Function Monte Carlo calculations on simple triatomic systems such as the reaction between hydrogen atoms and hydrogen molecules. In his recent calculations on the complete 4-body hydrogen molecule calculation, he was able to achieve a sustained speed of 1.5 gigaflop on a 65K processor CM-2 computer, with an overall accuracy of 0.006 Kcal/mole. Anderson will study the reaction surfaces for the hydrogen exchange reaction using the same approach, with the expectation of accuracies better than 0.01 Kcal/mole over the entire potential energy surface. He also expects to study the potential energy surface for the flourine atom plus hydrogen molecule reaction. Other systems to be studied include excitons in semiconductor crystallites, extended molecular systems consisting of small polyatomic molecules, and clusters of helium atoms. %%% The calculations which will be done in this project are important because they form an exact benchmark against which other electronic structure theoretical models can be tested.