AI 中文总结
研究针对跨相关哈密顿量，采用插值可分离密度拟合近似结合有效两体处理，使跨相关框架适用于大型系统，降低成本。通过线性氢链和苯基态能量计算验证方法，在精度和外推稳健性上优于传统耦合簇方法。
AI 中文摘要
跨相关（TC）方法通过相似变换将Jastrow相关器纳入哈密顿量，将电子-电子尖点纳入有效相互作用，极大地加速了相关计算向完备基组（CBS）极限的收敛。我们通过用插值可分离密度拟合（ISDF）近似压缩网格评估的TC积分，并结合三体算符的有效两体（xTC）处理，使TC框架适用于大型系统和灵活的多中心相关器。这种低秩表示将存储和积分成本降低了几个数量级，并且具有相关器自动微分的多GPU实现使得大基组的构建程序成为可能。我们在线性氢链上展示了由此产生的ISDF-xTC-CCSD方法，使用高达cc-pV5Z的基组达到联合热力学和CBS极限，与最先进的多体参考文献一致，误差在约1~mHa/原子以内；在苯基态能量计算中，使用高达1200个轨道（cc-pCV5Z），该方法在耦合簇单双激发水平上达到了最先进的精度，并且其CBS外推比传统耦合簇方法明显更稳健。
英文摘要
The transcorrelated (TC) method dramatically accelerates the convergence of correlated calculations toward the complete-basis-set (CBS) limit by folding a Jastrow correlator into the Hamiltonian via a similarity transformation, incorporating the electron--electron cusp into the effective interaction. We make the TC framework practical for large systems and flexible, multi-center correlators by compressing the grid-evaluated TC integrals with the interpolative separable density-fitting (ISDF) approximation, combined with the effective two-body (xTC) treatment of the three-body operator. This low-rank representation reduces storage and integration costs by orders of magnitude, and a multi-GPU implementation with automatic differentiation of the correlator makes the construction routine for large basis sets. We demonstrate the resulting ISDF-xTC-CCSD method on the linear hydrogen chain, reaching the joint thermodynamic and CBS limits with basis sets up to cc-pV5Z in agreement with state-of-the-art many-body references to within about 1~mHa/atom, and on the benzene ground-state energy with up to 1200 orbitals (cc-pCV5Z), where the method attains state-of-the-art accuracy at the coupled cluster singles and doubles level and its CBS extrapolation is markedly more robust than that of conventional coupled-cluster methods.
