论文标题
振动热浴配置相互作用
Vibrational Heat-Bath Configuration Interaction
论文作者
论文摘要
我们引入振动热浴构型相互作用（VHCI），作为计算Anharmonic Systems振动本特征状态的准确有效方法。 VHCI受到电子结构理论的起源的启发，是一种选定的CI方法，它使用简单的标准用Anharmonic Force常数列表来识别重要的基础状态。筛选的二阶扰动理论和简单的外推技术为变分能量估计值提供了重大改进。我们在四个分子上基准VHCI，具有12至48度的自由度，并使用第四和第六阶截断的非谐势能表面。对于所有研究的分子，VHCI均以低计算成本的亚波准确度产生数十个或数百个状态的振动光谱。
We introduce vibrational heat-bath configuration interaction (VHCI) as an accurate and efficient method for calculating vibrational eigenstates of anharmonic systems. Inspired by its origin in electronic structure theory, VHCI is a selected CI approach that uses a simple criterion to identify important basis states with a pre-sorted list of anharmonic force constants. Screened second-order perturbation theory and simple extrapolation techniques provide significant improvements to variational energy estimates. We benchmark VHCI on four molecules with 12 to 48 degrees of freedom and use anharmonic potential energy surfaces truncated at fourth and sixth order. For all molecules studied, VHCI produces vibrational spectra of tens or hundreds of states with sub-wavenumber accuracy at low computational cost.
