Weber Lukas, Dos Anjos Cunha Leonardo, Morales Miguel A, Rubio Angel, Zhang Shiwei
Center for Computational Quantum Physics, The Flatiron Institute, 162 Fifth Avenue, New York, New York, 10010, United States.
Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany.
J Chem Theory Comput. 2025 Mar 25;21(6):2909-2917. doi: 10.1021/acs.jctc.4c01459. Epub 2025 Jan 17.
We present a generalization of the phaseless auxiliary-field quantum Monte Carlo (AFQMC) method to cavity quantum-electrodynamical (QED) matter systems. The method can be formulated in both the Coulomb and the dipole gauge. We verify its accuracy by benchmarking calculations on a set of small molecules against full configuration interaction and state-of-the-art QED coupled cluster (QED-CCSD) calculations. Our results show that (i) gauge invariance can be achieved within correlation-consistent Gaussian basis sets, (ii) the accuracy of QED-CCSD can be enhanced significantly by adding the standard perturbative triples correction without light-matter coupling, and (iii) there is a straightforward way to evaluate the differential expression for the photon occupation number that works in any gauge. The high accuracy and favorable computational scaling of our AFQMC approach will enable a broad range of applications. Besides polaritonic chemistry, the method opens a way to simulate extended QED matter systems.
我们提出了一种将无相位辅助场量子蒙特卡罗（AFQMC）方法推广到腔量子电动力学（QED）物质系统的方法。该方法可以在库仑规范和偶极规范中进行表述。我们通过针对一组小分子进行基准计算，与完全组态相互作用以及最新的QED耦合簇（QED - CCSD）计算进行对比，验证了其准确性。我们的结果表明：（i）在相关一致的高斯基组内可以实现规范不变性；（ii）通过添加无光 - 物质耦合的标准微扰三重态修正，可以显著提高QED - CCSD 的精度；（iii）有一种直接的方法来评估光子占据数的微分表达式，该方法在任何规范下都有效。我们的AFQMC方法的高精度和良好的计算标度将使其能够广泛应用。除了极化子化学外，该方法还为模拟扩展的QED物质系统开辟了一条途径。
