摘要
It is well known that the Cr—Cr bond length, 1.68 （?）, 2.5（?）, observed in Cr<sub>2</sub> is much shorter than that in the bulk of metal Cr, 2.5A. In the view that this evidence may relate to the existence of metal-metal multiple bonds, considerable theoretical interests have been focused on Cr<sub>2</sub>. In the early 80’s, ab initio and configuration interaction （CI） calculations on
基金
Project supported by the National Natural Science Foundation of China
