Analytic gradients for state-averaged multiconfiguration pair-density functional theory.
Analytic gradients for state-averaged multiconfiguration pair-density functional theory.
复制标题
状态平均多配置对密度泛函理论的解析梯度。
DOI：
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发表时间：
2020
影响因子：
4.4
通讯作者：
L. Gagliardi
中科院分区：
文献类型：
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作者：
Thais R. Scott;M. Hermes;A. Sand;Meagan S. Oakley;D. Truhlar;L. Gagliardi
解析梯度对于有效地计算势能表面上的固定点、解释光谱观测和有效的直接动力学模拟都很重要。对于激发态的电子，如涉及到紫外-可见光谱学和光化学，分析梯度是很容易获得的，并且通常使用状态平均的完全主动空间自一致场（SA-CASSCF）波函数进行计算。然而，在大多数情况下，sa - casscf后步骤对于定量精度是必要的，如果通过摄动理论或组态相互作用进行此类计算通常过于昂贵。在这项工作中，我们提出了基于SA-CASSCF波函数的多组态对密度泛函理论的解析梯度，这是一种更实惠的替代方案。用该方法对一组测试分子进行了研究，并与文献中用其他方法得到的静态几何和能量学值进行了比较。用状态平均对密度泛函理论计算的激发态几何在二阶上与完全主动空间摄动理论计算的几何具有相似的精度。
Analytic gradients are important for efficient calculations of stationary points on potential energy surfaces, for interpreting spectroscopic observations, and for efficient direct dynamics simulations. For excited electronic states, as are involved in UV-Vis spectroscopy and photochemistry, analytic gradients are readily available and often affordable for calculations using a state-averaged complete active space self-consistent-field (SA-CASSCF) wave function. However, in most cases, a post-SA-CASSCF step is necessary for quantitative accuracy, and such calculations are often too expensive if carried out by perturbation theory or configuration interaction. In this work, we present the analytic gradients for multiconfiguration pair-density functional theory based on SA-CASSCF wave functions, which is a more affordable alternative. A test set of molecules has been studied with this method, and the stationary geometries and energetics are compared to values in the literature as obtained by other methods. Excited-state geometries computed with state-averaged pair-density functional theory have similar accuracy to those from complete active space perturbation theory at the second-order.