Pitarch-Ruiz J, Sánchez-Marín J, Velasco A M
Institut de Ciencia Molecular, Universitat de València, Campus de Paterna, Paterna E-46980 (Valencia), Spain.
J Comput Chem. 2008 Mar;29(4):523-32. doi: 10.1002/jcc.20811.
The all-electron full configuration interaction (FCI) vertical excitation energies for some low lying valence and Rydberg excited states of BeH are presented in this article. A basis set of valence atomic natural orbitals has been augmented with a series of Rydberg orbitals that have been generated as centered onto the Be atom. The resulting basis set can be described as 4s2p1d/2s1p (Be/H) + 4s4p3d. It allows to calculate Rydberg states up to n= {3,4,5} of the s, p, and d series of Rydberg states. The FCI vertical ionization potential for the same basis set and geometry amounts to 8.298 eV. Other properties such as FCI electric dipole and quadrupole moments and FCI transition dipole and quadrupole moments have also been calculated. The results provide a set of benchmark values for energies, wave functions, properties, and transition properties for the five electron BeH molecule. Most of the states have large multiconfigurational character in spite of their essentially single excited nature and a number of them present an important Rydberg-valence mixing that is achieved through the mixed nature of the particle MO of the single excitations.
本文给出了BeH一些低能价态和里德堡激发态的全电子全组态相互作用（FCI）垂直激发能。价层原子自然轨道基组已通过一系列以Be原子为中心生成的里德堡轨道进行了扩充。所得基组可描述为4s2p1d/2s1p（Be/H）+4s4p3d。它能够计算s、p和d系列里德堡态直至n={3,4,5}的里德堡态。相同基组和几何结构下的FCI垂直电离势为8.298 eV。还计算了其他性质，如FCI电偶极矩和四极矩以及FCI跃迁偶极矩和四极矩。这些结果为五电子BeH分子的能量、波函数、性质和跃迁性质提供了一组基准值。尽管大多数态本质上是单激发性质，但它们具有很大的多组态特征，其中一些态呈现出重要的里德堡-价态混合，这是通过单激发的粒子分子轨道的混合性质实现的。
