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arXiv 2602.06149physics.chem-ph
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Kohn-Sham密度编码拯救耦合簇理论用于强相关分子

Kohn-Sham density encoding rescues coupled cluster theory for strongly correlated molecules

University of Pittsburgh(匹兹堡大学)

Abdulrahman Y. Zamani, Barbaro Zulueta, Andrew M. Ricciuti, John A. Keith, Kevin Carter-Fenk

AI总结:

Kohn-Sham密度编码使耦合簇理论在强相关分子计算中实现高精度,恢复Cr₂势能面并提升热化学性质预测

摘要:

耦合簇理论结合Kohn-Sham参考(KS-CC)可以在强相关系统中大幅超越其Hartree-Fock对应物,但这些改进的起源仍不清楚。在这里我们证明这些改进来自于非规范Fock矩阵中编码的一粒子密度矩阵的差异,而不是KS轨道的性质,这通常被假设。借助这一见解,KS-CCSD(T)可以被利用以实现过渡金属二聚体和主族化合物的电子和热化学性质的近化学精度。最引人注目的是,KS-CCSD(T)定性地恢复了Cr₂势能面,这是HF-CCSD(T)和单参考密度泛函理论的著名失败案例。我们进一步引入了密度差诊断,以识别多参考特征并指导从业者在平均场成本下合理选择最优参考。这些结果确立了KS-CCSD(T)作为在“黄金标准”框架内处理强相关性的一种实用途径,这对机器学习势能开发和材料研究有直接的影响,这些领域严重依赖KS-DFT进行模型参数拟合。

英文摘要:

Coupled cluster theory with a Kohn-Sham reference (KS-CC) can dramatically outperform its Hartree-Fock counterpart for strongly correlated systems, but the origin of these improvements has remained unclear. Here we demonstrate that these improvements arise from differences in the one-particle density matrix that are encoded into the non-canonical Fock matrix and not from the nature of the KS orbitals, as is commonly assumed. Equipped with this insight, KS-CCSD(T) can be leveraged to achieve near-chemical-accuracy for electronic and thermochemical properties of transition-metal dimers and main-group compounds. Most strikingly, KS-CCSD(T) qualitatively recovers the entire Cr$_2$ potential energy surface, a notorious failure case for HF-CCSD(T) and single-reference density functional theory. We further introduce a density difference diagnostic that identifies multireference character and guides practitioners toward rational selections of optimal references at mean-field cost. These results establish KS-CCSD(T) as a practical route to treat strong correlation within the "gold standard" framework, and this has immediate implications for machine learning potential development and materials research, areas that heavily rely on KS-DFT for model-parameter fitting.

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。

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