Karl-Franzens Universität, Institut für Chemie, Heinrichstraße 28/IV, Graz A-8010, Austria.
Université de Lorraine, CNRS, SRSMC UMR 7565, Faculté des Sciences et Technologies, Boulevard des Aiguillettes BP 70239, Vandoeuvre-lès-Nancy Cedex F-54506, France.
J Chem Phys. 2017 Oct 28;147(16):161718. doi: 10.1063/1.4995569.
Models of atomic electric multipoles for the water molecule have been optimized in order to reproduce the electric potential around the molecule computed by ab initio calculations at the coupled cluster level of theory with up to noniterative triple excitations in an augmented triple-zeta quality basis set. Different models of increasing complexity, from atomic charges up to models containing atomic charges, dipoles, and quadrupoles, have been obtained. The geometry dependence of these atomic multipole models has been investigated by changing bond lengths and HOH angle to generate 125 molecular structures (reduced to 75 symmetry-unique ones). For several models, the atomic multipole components have been fitted as a function of the geometry by a Taylor series of fourth order in monomer coordinate displacements.
为了重现通过耦合簇理论在augmented triple-zeta 质量基组上进行高达非迭代三重激发计算得到的水分子周围的电势，已经优化了水分子的原子电多极模型。已经获得了从原子电荷到包含原子电荷、偶极子和四极子的模型的不同复杂程度的模型。通过改变键长和HOH 角来生成 125 个分子结构（减少到 75 个对称独特的分子结构），研究了这些原子多极模型的几何依赖性。对于几个模型，已经通过在单体坐标位移的四阶泰勒级数将原子多极分量拟合为几何函数。
