运动方程规范化轨道优化的二次扰动理论与密度合适的近似方法.
1Department of Chemistry, Hacettepe University, Ankara 06800, Turkey.
The Journal of chemical physics
|September 16, 2024
概括
新的计算方法,K-DF-EOM-OMP2和K-DF-EOM-MP2,为化学系统提供高度准确的激发能量. 这些方法以较低的成本接近合集群质量,为激发状态研究提供了宝贵的工具.
科学领域:
- 计算化学的计算化学
- 量子化学 是一个量子化学.
- 理论化学 理论化学
背景情况:
- 精确计算激发能量对于理解分子特性和化学反应至关重要.
- 现有的方法,如密度装配的EOM-MP2 (DF-EOM-MP2),对某些系统的准确性有局限性.
- 结合集群方法虽然准确,但在计算上是昂贵的.
研究的目的:
- 引入和实施新型密度拟合运动方程 (DF-EOM) 方法,包括 κ-规范化.
- 评估用于计算激发能量的新 κ-DF-EOM-MP2 和 κ-DF-EOM-OMP2 方法的准确性.
- 将这些新方法的性能与已建立的DF-EOM-MP2,DF-EOM-OMP2和合集群方法进行比较.
主要方法:
- 开发和实施密度调整的运动方程轨道优化二次扰动理论 (DF-EOM-OMP2).
- 在DF-EOM-MP2和DF-EOM-OMP2方法中引入 κ-规范化,创建 κ-DF-EOM-MP2和 κ-DF-EOM-OMP2.
- 对各种封闭和开放系统中激发能量的高层EOM-CCSD (fT) 计算进行验证.
主要成果:
- κ调节技术显著提高了激发能量计算的准确性,特别是对于第一个激发状态.
- κ-DF-EOM-MP2和 κ-DF-EOM-OMP2方法在与其非规范化的对应方法 (DF-EOM-MP2和 DF-EOM-OMP2) 相比显示出更高的性能.
- 新的 κ-方法以较低的计算成本实现了与 EOM-CCSD 质量相当的准确性.
结论:
- κ-DF-EOM-MP2 和 κ-DF-EOM-OMP2 方法代表了对激发能量的计算效率和准确性的重大进步.
- 特别是 κ-DF-EOM-MP2 方法,在各种测试案例中显示出出色的结果.
- 这些 κ-版本被提出为研究激发状态分子性质的有价值的计算工具.
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