基于MP2的校正方案,以接近DLPNO-CCSD中的完整对自然轨道空间的极限
James Pogrebetsky1, Alexandra Siklitskaya1, Adam Kubas1
1Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warszawa 01-224, Poland.
Journal of chemical theory and computation
|June 20, 2023
概括
一个新的扰动性校正方案提高了基于域的局部对自然轨道合集群 (DLPNO-CCSD(T)) 计算的准确性. 这种方法有效地实现了封闭和开放系统的化学精度.
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:
- 基于域的局部对自然轨道合集群 (DLPNO-CCSD(T)) 与正规的CCSD(T)) 相比,以降低的计算成本提供精确的能量.
- 使用DLPNO-CCSD (T) 实现"化学精度"需要很大的PNO空间和广泛的基础集,增加计算需求.
- 开放系统对局部相关的方法提出了特殊的挑战.
研究的目的:
- 为DLPNO-CCSD计算开发一个简单,准确和高效的校正方案.
- 为了使相对应能量的完整PNO空间 (cPNO) 极限的成本效益达到.
- 为了提高DLPNO-CCSD的准确性,无论是封闭式还是开放式系统.
主要方法:
- 通过计算 DLPNO-MP2 与 DLPNO-CCSD ((T)) 相关性能量的同时进行扰动性校正.
- 规范MP2相关性能量是以相同的轨道基础计算的,以便进行比较.
- 规范和DLPNO-MP2能量之间的差异被用作DLPNO-CCSD (T) 相对应能量的修正项.
主要成果:
- 提出的方法有效地回收接近cPNO极限的相关性能量.
- 在封闭和开放系统中观察到显著的精度改进.
- 该方法提供了一个成本效益高的替代方案,以PNO推断程序,在计算时间的最小增加.
结论:
- 开发的校正方案提高了DLPNO-CCSD计算的准确性.
- 这种方法有效地实现了对各种分子系统的高精度,与cPNO极限相当.
- 该方法为在计算化学中获得可靠和准确的电子结构数据提供了实用解决方案.
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