Investigation of challenging spin systems using Monte Carlo configuration interaction and the density matrix renormalization group.
Investigation of challenging spin systems using Monte Carlo configuration interaction and the density matrix renormalization group.
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使用蒙特卡罗构型相互作用和密度矩阵重正化群研究具有挑战性的自旋系统。
DOI：
10.1002/jcc.25057
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发表时间：
2017
影响因子：
3
通讯作者：
Coe JP
中科院分区：
文献类型：
--
作者：
Coe JP
我们研究了一系列具有挑战性的自旋系统是否可以用蒙特卡罗配置相互作用（MCCI）和密度矩阵重整化群（DMRG）以一种更接近“黑箱”方法的方式充分描述。实验结果与其他计算方法进行了比较。首先考虑了甲基苯胺（CH）最低重态和四重态之间的间隙。然后，我们看看一系列第一排过渡金属单羰基：当M是钛、钒、铬或锰时的MCO。对于这些MCO系统，我们还采用了部分自旋受限开壳耦合簇（RCCSD）。我们最后研究了铁二聚体的高自旋低洼态、阳离子态和阴离子态。还考虑了这些分子的多参考特性。我们发现这些系统具有接近的低洼状态和多参考特性，在计算上具有挑战性。对于这种更直接的应用和考虑的基集，我们通常发现DMRG和MCCI之间的定性一致。©2017 Wiley期刊公司
We investigate if a range of challenging spin systems can be described sufficiently well using Monte Carlo configuration interaction (MCCI) and the density matrix renormalization group (DMRG) in a way that heads toward a more “black box” approach. Experimental results and other computational methods are used for comparison. The gap between the lowest doublet and quartet state of methylidyne (CH) is first considered. We then look at a range of first‐row transition metal monocarbonyls: MCO when M is titanium, vanadium, chromium, or manganese. For these MCO systems we also employ partially spin restricted open‐shell coupled‐cluster (RCCSD). We finally investigate the high‐spin low‐lying states of the iron dimer, its cation and its anion. The multireference character of these molecules is also considered. We find that these systems can be computationally challenging with close low‐lying states and often multireference character. For this more straightforward application and for the basis sets considered, we generally find qualitative agreement between DMRG and MCCI. © 2017 Wiley Periodicals, Inc.