论文标题
从头开始耦合群集理论的金属固体的地面特性
Ground-state properties of metallic solids from ab initio coupled-cluster theory
论文作者
论文摘要
金属固体是基于波函数的电子结构理论的具有挑战性的目标，并且尚未通过这种方法进行详细研究。在这里，我们将群集理论与单激励（CCSD）（CCSD）一起使用优化的高斯基集研究固体锂和铝的结构。我们计算平衡晶格常数，散装模量和内聚能量，并将它们与实验值进行比较，找到与公共密度函数相当的精度。由于量子化学“金标准” CCSD（t）（带有扰动三重激发的CCSD）在热力学极限下对金属不适用，因此我们测试了CCSD的两个近似改进，发现这可以改善预测的凝聚力。
Metallic solids are a challenging target for wavefunction-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 predicted cohesive energies.
