Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, P.O. Box 64 004, 157 10 Zografou, Athens, Greece.
J Phys Chem A. 2010 Aug 26;114(33):8536-72. doi: 10.1021/jp910218u.
The diatomic neutral oxides and their ions, MO(0,+/-), M = Sc, Ti, Cr, and Mn, have been studied through multireference configuration interaction and coupled-cluster methods. With the purpose to paint a more comprehensive and detailed picture on these not so easily tamed systems, we have constructed complete potential energy curves for a large number of states of all MO(0,+/-)'s reporting structural and spectroscopic properties. Our overall results are in very good agreement with the, in general limited, experimental data. The always difficult to be pinpointed "nature of the chemical bond" becomes more recondite for these highly open ionic-covalent species. We have tried to give some answers as to the bonding interactions using simple valence-bond-Lewis diagrams in conjunction with Mulliken populations and the symmetry of the in situ atoms. It is our belief that, particularly for this kind of molecule, molecular orbital concepts are of limited help for a consistent rationalization of the bond formation.
双原子中性氧化物及其离子 MO(0, +/-)（M = Sc、Ti、Cr 和 Mn）已通过多参考组态相互作用和耦合簇方法进行了研究。为了更全面、更详细地了解这些不易控制的体系，我们为所有 MO(0, +/-)的大量状态构建了完整的势能曲线，报告了结构和光谱性质。我们的总体结果与一般有限的实验数据非常吻合。对于这些高度开放的离子-共价物种，“化学键的本质”总是难以确定。我们试图使用简单的价键-路易斯图结合 Mulliken 布居数和原位原子的对称性来给出一些关于成键相互作用的答案。我们相信，特别是对于这种分子，分子轨道概念对于一致合理化键合形成的帮助有限。
