变量主动空间选择与多配置对密度函数理论
Daniel S King1, Donald G Truhlar2, Laura Gagliardi3
1Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.
Journal of chemical theory and computation
|October 31, 2023
概括
我们开发了一种离散变量选择 (DVS) 方法,用于在电子结构计算中选择活性轨道. 这种DVS-tPBE方法准确地模拟了复杂的分子状态,提高了计算化学的准确性.
科学领域:
- 计算化学的计算化学
- 量子化学 是一个量子化学.
- 电子结构理论 电子结构理论
背景情况:
- 为强烈相关的电子状态选择活跃轨道是具有挑战性和分子依赖的.
- 现有的方法在自动化活动空间选择方面缺乏普遍适用性.
- 准确的电子状态建模对于理解分子性质至关重要.
研究的目的:
- 引入和验证一种新的离散变量选择 (DVS) 方法,用于自动化的活跃空间选择.
- 为了评估DVS的有效性,使用不同的能量函数来选择试验波函数.
- 应用优化的DVS方法来模拟有机和无机分子中的垂直激发.
主要方法:
- 从系统构建的活跃空间生成多个试验波函数.
- 在多重配置对密度函数理论 (MC-PDFT) 中使用来自翻译PBE (tPBE) 函数的能量在波函数之间采用变化选择.
- 从QUESTDB数据库中应用DVS-tPBE方法对207个中小分子的垂直激发.
主要成果:
- 在密度矩阵重规范化组 (DMRG) 或完全活跃空间自相一致场 (CASSCF) 能量下,DVS被证明是无效的.
- DVS-tPBE表现出良好的性能,使用混合MC-PDFT进行垂直激发,平均无标记误差为0.17 eV.
- 该DVS-tPBE方法实现了基准准确度,而不过弱活跃空间或需要进一步的轨道优化.
结论:
- 离散变量选择 (DVS) 方法,特别是DVS-tPBE,为主动空间选择提供了一种强大而有效的方法.
- 这种方法准确地模拟了状态平均的DMRG波函数,并与以前的SA-CASSCF结果进行了有利的比较.
- DVS-tPBE推进了自动化的活性空间选择,增强了计算化学中强烈相关的电子状态的建模.
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