激发参考态Møller-Plesset微扰理论的收敛性
Convergence of Møller-Plesset perturbation theory for excited reference states
摘要：
分子中的激发态可能难以研究，并且通常需要计算昂贵或不普遍准确的方法。最近的研究集中在使用更高能量的斯莱特行列式作为激发态的平均场表示，然后可以用来定义电子相关技术（如Møller-Plesset理论）的参考态。然而，这些激发态微扰序列的收敛行为尚未被探索，限制了我们对这种方法的系统改进性和可靠性的理解。在这里，我们提出了一个系统的分析的Møller-Plesset微扰系列的闭壳层激发态使用较高的能量参考行列式确定，和没有，国家特定的轨道优化。我们结合数值计算与复杂的分析表明，激发态Møller-Plesset理论分歧几乎普遍的定型$\mathrm{H}_2$，$\mathrm{H}_2\mathrm{O}$，和$\mathrm{CH}_2$分子。我们的研究结果对高能斯莱特行列式作为电子相关微扰处理参考态的适用性表示怀疑。
英文摘要：
Excited states in molecules can be difficult to investigate and generally require methods that are either computationally expensive or are not universally accurate. Recent research has focused on using higher-energy Slater determinants as mean-field representations of excited states, which can then be used to define reference states for electron correlation techniques such as Møller-Plesset theory. However, the convergence behaviour of these excited-state perturbation series has not yet been explored, limiting our understanding into the systematic improvability and reliability of such methods. Here, we present a systematic analysis of the Møller-Plesset perturbation series for closed-shell excited states using higher-energy reference determinants identified with, and without, state-specific orbital optimisation. We combine numerical calculations with complex analysis to show that the excited-state Møller-Plesset theory diverges almost universally for the stereotypical $\mathrm{H}_2$, $\mathrm{H}_2\mathrm{O}$, and $\mathrm{CH}_2$ molecules. Our results cast doubt on the suitability of higher-energy Slater determinants as reference states for perturbative treatments of electron correlation.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
