论文标题
在无量相辅助场中选定的配置相互作用波函数
Selected configuration interaction wave functions in phaseless auxiliary field quantum Monte Carlo
论文作者
论文摘要
我们提出了使用所选构型相互作用（SCI）试验波函数中的有效算法，该算法函数在无量音辅助场量子量蒙特卡洛（pH-AFQMC）中。这些进步旨在为更长的CI扩展优化计算性能，使我们可以在PH-AFQMC的试验状态下最多使用一百万个配置。在一个示例中，我们发现每个样本的pH-AFQMC成本仅增加了约3美元的$ 3 $，与单个配置相比，$ 10^4 $配置的计算成本仅增加了$ 3 $，这表明由于较长的扩展而显示了微小的计算开销。这种有利的缩放使我们能够以越来越多的配置来研究AFQMC计算中无相位偏置的系统收敛性，并提供了一种方法，以评估pH-AFQMC与其他试验状态的准确性。我们还展示了如何通过将其限制到适度尺寸的轨道活动空间并利用活跃空间无用的无相相错误的几乎融合来减轻SCI试验状态的可伸缩性问题。
We present efficient algorithms for using selected configuration interaction (sCI) trial wave functions in phaseless auxiliary field quantum Monte Carlo (ph-AFQMC). These advancements, geared towards optimizing computational performance for longer CI expansions, allow us to use up to a million configurations feasibly in the trial state for ph-AFQMC. In one example, we found the cost of ph-AFQMC per sample to increase only by a factor of about $3$ for a calculation with $10^4$ configurations compared to that with a single one, demonstrating the tiny computational overhead due to a longer expansion. This favorable scaling allows us to study the systematic convergence of the phaseless bias in AFQMC calculations with an increasing number of configurations and provides a means to gauge the accuracy of ph-AFQMC with other trial states. We also show how the scalability issues of sCI trial states for large system sizes could be mitigated by restricting them to a moderately sized orbital active space and leveraging the near-cancellation of out of active space phaseless errors.
