对于激发状态的特定国家合集群方法
Yann Damour1, Anthony Scemama1, Denis Jacquemin2,3
1Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France.
Journal of chemical theory and computation
|May 15, 2024
概括
我们评估了 ΔCCSD 方法来计算分子激发状态,发现它对双倍激发状态有效,但对其他类型的 EOM-CCSD 准确性通常不如 EOM-CCSD. 国家特定轨道提供了轻微的改进.
科学领域:
- 量子化学 是一个量子化学.
- 计算化学计算化学
- 理论化学 理论化学
背景情况:
- 标准的单次和双次激发的运动方程合集群 (EOM-CCSD) 方法与双倍激发的状态作斗争.
- 使用非奥夫巴乌决定因素的 ΔCCSD 方法为准兴奋状态提供了替代方案,特别是双重兴奋状态.
研究的目的:
- 为了对 ΔCCSD 方法与 EOM-CCSD 对各种类型的分子激发状态的准确性和一致性进行基准测试.
- 评估超出双激发状态的 ΔCCSD 的性能,包括闭系统的双倍-双倍过渡和单次激发状态.
主要方法:
- 对 ΔCCSD 和 EOM-CCSD 计算激发能量的方法进行比较.
- 利用从任务数据库中获得的276个激发状态的数据集.
- 在封闭外系统中采用极简主义的两决定因素合集群方法,用于单独激发的状态.
主要成果:
- ΔCCSD对双激发状态显示有效性,但对其他激发类型的表现通常低于EOM-CCSD.
- 双倍-双倍过渡的平均绝对误差 (MAE) 是0.10 eV (ΔCCSD) 与0.07 eV (EOM-CCSD) 相比.
- 单次激发状态的MAE为0.15 eV (ΔCCSD) 与0.08 eV (EOM-CCSD) 相比,具有更高的多配置特征,有助于 ΔCCSD 的精度降低.
结论:
- CCSD是用于EOM-CCSD失败的双重激发状态的可行方法.
- 对于大多数其他兴奋状态,EOM-CCSD仍然是更准确和更一致的选择.
- 国家特定的优化轨道为 ΔCCSD 精度提供了边际改进.
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