Brumboiu Iulia Emilia, Rehn Dirk R, Dreuw Andreas, Rhee Young Min, Norman Patrick
Department of Chemistry, Pohang University of Science and Technology (POSTECH), 37673 Pohang, Republic of Korea.
Interdisciplinary Center for Scientific Computing, Heidelberg University, 69120 Heidelberg, Germany.
J Chem Phys. 2021 Jul 28;155(4):044106. doi: 10.1063/5.0058221.
Expressions for analytical molecular gradients of core-excited states have been derived and implemented for the hierarchy of algebraic diagrammatic construction (ADC) methods up to extended second-order within the core-valence separation (CVS) approximation. We illustrate the use of CVS-ADC gradients by determining relaxed core-excited state potential energy surfaces and optimized geometries for water, formic acid, and benzene. For water, our results show that in the dissociative lowest core-excited state, a linear configuration is preferred. For formic acid, we find that the O K-edge lowest core-excited state is non-planar, a fact that is not captured by the equivalent core approximation where the core-excited atom with its hole is replaced by the "Z + 1" neighboring atom in the periodic table. For benzene, the core-excited state gradients are presented along the Jahn-Teller distorted geometry of the 1s → π* excited state. Our development may pave a new path to studying the dynamics of molecules in their core-excited states.
在芯价分离（CVS）近似下，已推导并实现了直至扩展二阶代数图示构建（ADC）方法层级的芯激发态解析分子梯度表达式。我们通过确定水、甲酸和苯的弛豫芯激发态势能面及优化几何结构，来说明CVS-ADC梯度的用途。对于水，我们的结果表明，在解离性最低芯激发态中，线性构型更受青睐。对于甲酸，我们发现O K边最低芯激发态是非平面的，这一事实在等效芯近似中未被捕捉到，在等效芯近似中，带有空穴的芯激发原子被周期表中“Z + 1”相邻原子取代。对于苯，沿1s → π*激发态的 Jahn-Teller 畸变几何结构给出了芯激发态梯度。我们的进展可能为研究分子在其芯激发态下的动力学开辟一条新途径。
