论文标题
改进的快速随机迭代方法进行完整配置交互
Improved Fast Randomized Iteration Approach to Full Configuration Interaction
论文作者
论文摘要
我们向最近引入的快速随机迭代方法提供了三个修改，以进行完整配置交互（FCI-FRI），并研究了它们对NE，H $ _2 $ O和N $ _2 $的方法的影响。最初用于完整构型相互作用量子蒙特卡洛（Monte Carlo）开发的引发剂近似可显着降低FCI-FRI的统计误差，当时很少有样品用于压缩操作，从而使其适用于较大的化学系统。半传导的扩展涉及在每种压缩中精确保留元素的固定子集，在某些情况下可以提高统计效率，但在其他情况下会降低。我们还开发了一种新的方法来抽取激发，从而在统计效率和计算成本降低方面持续提高。我们根据我们的发现，以更广泛地提高随机量子化学方法的性能来讨论可能的策略。
We present three modifications to our recently introduced fast randomized iteration method for full configuration interaction (FCI-FRI) and investigate their effects on the method's performance for Ne, H$_2$O, and N$_2$. The initiator approximation, originally developed for full configuration interaction quantum Monte Carlo, significantly reduces statistical error in FCI-FRI when few samples are used in compression operations, enabling its application to larger chemical systems. The semi-stochastic extension, which involves exactly preserving a fixed subset of elements in each compression, improves statistical efficiency in some cases but reduces it in others. We also developed a new approach to sampling excitations that yields consistent improvements in statistical efficiency and reductions in computational cost. We discuss possible strategies based on our findings for improving the performance of stochastic quantum chemistry methods more generally.
