Neufeld Verena A, Ye Hong-Zhou, Berkelbach Timothy C
Department of Chemistry, Columbia University, New York, New York 10027, United States.
Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, United States.
J Phys Chem Lett. 2022 Aug 18;13(32):7497-7503. doi: 10.1021/acs.jpclett.2c01828. Epub 2022 Aug 8.
Metallic solids are an enormously important class of materials, but they are a challenging target for accurate wave function-based electronic structure theories and have not been studied in great detail by such methods. Here, we use coupled-cluster theory with single and double excitations (CCSD) to study the structure of solid lithium and aluminum using optimized Gaussian basis sets. We calculate the equilibrium lattice constant, bulk modulus, and cohesive energy and compare them to experimental values, finding accuracy comparable to common density functionals. Because the quantum chemical "gold standard" CCSD(T) (CCSD with perturbative triple excitations) is inapplicable to metals in the thermodynamic limit, we test two approximate improvements to CCSD, which are found to improve the results.
金属固体是一类极其重要的材料，但对于基于精确波函数的电子结构理论而言，它们是具有挑战性的研究对象，并且尚未通过此类方法进行详细研究。在此，我们使用含单双激发的耦合簇理论（CCSD），采用优化的高斯基组来研究固体锂和铝的结构。我们计算了平衡晶格常数、体模量和内聚能，并将它们与实验值进行比较，发现其精度与常见的密度泛函相当。由于量子化学的“金标准”CCSD(T)（含微扰三激发的CCSD）在热力学极限下不适用于金属，我们测试了对CCSD的两种近似改进方法，发现它们能改善结果。
