Mihm Tina N, Van Benschoten William Z, Shepherd James J
Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1294, USA.
J Chem Phys. 2021 Jan 14;154(2):024113. doi: 10.1063/5.0033408.
We recently developed a scheme to use low-cost calculations to find a single twist angle where the coupled cluster doubles energy of a single calculation matches the twist-averaged coupled cluster doubles energy in a finite unit cell. We used initiator full configuration interaction quantum Monte Carlo as an example of an exact method beyond coupled cluster doubles theory to show that this selected twist angle approach had comparable accuracy in methods beyond coupled cluster. Furthermore, at least for small system sizes, we show that the same twist angle can also be found by comparing the energy directly (at the level of second-order Moller-Plesset theory), suggesting a route toward twist angle selection, which requires minimal modification to existing codes that can perform twist averaging.
我们最近开发了一种方案，利用低成本计算来找到一个单一的扭转角，在此扭转角下，单次计算的耦合簇双激发能与有限晶胞中的扭转平均耦合簇双激发能相匹配。我们以引发剂全组态相互作用量子蒙特卡罗方法为例，它是一种超越耦合簇双激发理论的精确方法，以此表明这种选定扭转角的方法在超越耦合簇的方法中具有相当的准确性。此外，至少对于小系统规模，我们表明通过直接比较能量（在二阶莫勒-普列斯特定理水平）也能找到相同的扭转角，这为扭转角的选择提供了一条途径，该途径对现有能够进行扭转平均的代码只需进行最小程度的修改。
