Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium.
J Phys Chem A. 2009 Nov 26;113(47):13210-20. doi: 10.1021/jp903948k.
A quantitative characterization of the Rydberg and valence singlet electronic states of acetylene lying in the 5-10.7 eV region is performed by using large-scale ab initio calculations. A special attention is paid on the comparison between the present calculations and Mulliken's concepts for Rydberg states, based on single-electron and single-configuration description. Most of the properties of the Rydberg states have been qualitatively understood via this comparison, mainly shown by the shape and size of the outer Rydberg molecular orbital. More quantitatively, Rydberg-valence mixing has been evaluated in several excited energy regions, as for instance, the interaction between the ' (1pig)2 1Ag doubly excited valence state and the manifold of electronic components of the np series, or the interaction between the 1pig 1Bu valence state and the 3dpig 1Sigma(u)+ Rydberg state. The rapid predissociation of the lowest 3s(sigma) 1Piu Rydberg state has been interpreted as a case of Rydbergization, earlier predicted by Mulliken.
采用大规模从头计算方法对乙炔的 5-10.7eV 区域内的里德堡和价单重电子态进行了定量描述。特别关注了基于单电子和单构型描述的本计算与 Mulliken 里德堡态概念之间的比较。通过这种比较，主要通过外里德堡分子轨道的形状和大小，定性地理解了里德堡态的大部分性质。更定量地，在几个激发能区评估了里德堡-价混合，例如，“(1pig)2 1Ag 双重激发价态与 np 系列的电子分量的多重态之间的相互作用，或 1pig 1Bu 价态与 3dpig 1Sigma(u)+ 里德堡态之间的相互作用。最低的 3s(sigma) 1Piu 里德堡态的快速预解离被解释为里德堡化的一个例子，这是 Mulliken 早些时候预测的。
