第二级近似内部合同多重引用合集群单双方法的性能测试 icMRCC2
Patrik Zielinski1, Joshua A Black1, Andreas Köhn1
1Institute for Theoretical Chemistry, University of Stuttgart, Paffenwaldring 55, Stuttgart D-70569, Germany.
Journal of chemical theory and computation
|November 22, 2023
概括
内部承包的单次和双次激发的多引用合集群方法 (icMRCC2) 准确计算了分子性质,扩展了复杂系统的单参考方法的功能.
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:
- 单参考合集群方法CC2被广泛使用,但对具有强烈多参考特征的系统有局限性.
- 开发准确和高效的多参考方法对于理解复杂的电子结构至关重要.
研究的目的:
- 为了比较内部承包的单次和双次激发的多参考合集群方法 (icMRCC2) 的性能.
- 评估icMRCC2用于计算垂直激发能,光谱常数和几何参数的准确性.
- 为了证明icMRCC2对单一参考CC2的优势,用于具有挑战性的化学系统.
主要方法:
- 将icMRCC2方法应用于各种中小型有机分子和二氧化物.
- 将icMRCC2结果与已确定的文献数据和实验值进行比较.
- 研究活跃空间大小对icMRCC2精度的影响.
主要成果:
- icMRCC2准确地预测了垂直激发能量,光谱常数和几何参数.
- 该方法克服了CC2的局限性,包括Rydberg激发和多重债券的问题.
- 在icMRCC2.的小活性空间中,经常可以获得准确的结果.
结论:
- icMRCC2在准确性方面比标准的多参数扰动理论有显著的改进.
- 该方法将CC2的适用性扩展到具有强烈多参考特征的系统.
- icMRCC2显示出研究复杂化学现象的巨大潜力,包括过渡金属复合物的自动化和激发状态.
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