量子线性响应框架中的酉耦合簇核屏蔽常数

中文摘要 AI 辅助

我们在适用于量子计算的框架内完成了核磁共振光谱学的关键要素——核屏蔽常数的计算。我们采用量子线性响应（qLR）理论，结合酉耦合簇（UCC）近似及其轨道优化（oo-UCC）、因子化（fUCC）、轨道优化因子化（oo-fUCC）变体。针对7种小分子，以CASCI、CASSCF、CCSD和CCSD(T)计算为参考，评估了这些方法。不同基于UCC的qLR方法得到的屏蔽常数与可比经典方法吻合良好；因子化是量子计算实现的必要步骤，对计算得到的屏蔽常数影响可忽略；而轨道优化则带来显著改进，oo-UCC和oo-fUCC与CCSD、CCSD(T)的吻合度明显更好。我们的结果表明，oo-fUCC结合qLR是在量子计算机上计算核屏蔽常数的有前景方法。

英文摘要

We present calculations of nuclear shielding constants, a key ingredient in nuclear magnetic resonance spectroscopy, within a quantum-computing-suitable framework. We employ quantum linear response (qLR) theory in combination with the unitary coupled cluster (UCC) ansatz and its orbital-optimized (oo-UCC), factorized (fUCC), and orbital-optimized factorized (oo-fUCC) variants. The methods are assessed for seven small molecules against CASCI, CASSCF, CCSD, and CCSD(T) reference calculations. The different UCC-based qLR approaches yield shielding constants in good agreement with comparable classical methods. Factorization, which is necessary for quantum-computing implementations, has only a negligible effect on the calculated shielding constants. Orbital optimization, in contrast, leads to substantial improvements, with oo-UCC and oo-fUCC showing markedly better agreement with CCSD and CCSD(T). Our results establish oo-fUCC combined with qLR as a promising approach for computing nuclear shielding constants on quantum computers.

发表机构

• University of Copenhagen（哥本哈根大学）
• Technical University of Denmark（丹麦技术大学）
• University of Southern Denmark（南丹麦大学）

机构由 AI 辅助整理，请以论文原文为准。