过渡金属团簇Cr_n结构的理论研究

Theoretical Study on the Structure for Transition Metal Cluster Cr_n

应用量子化学从头算方法研究了纯过渡金属Cr团簇中的各种组态及金属键,在HF/Lanl2DZ水平进行了研究,并用MP2做了电子相关能校正.通过对其几何结构和电子结构的研究预测:Cr3团簇有直线、V形、正三角形构型;Cr4有平面构型也有立体构型,平面构型原子间存在强弱键现象,即原子间存在定域键;Cr5、Cr6则有平面构型也有立体构型,平面构型有定域键也有离域键,立体构型则都是离域键.

A theoretical study of quantum chemistry was carried out for structure of transition metal cluster Cr.After analyzing the electronic and geometrical structure,we found that the trimer of chromium may be straight line,broken line or equilateral triangle configuration.The Cr_4 isomers are mostly planar structures:square,rectangle,rhombus…another are linear structures.There are some strong-weak bonds between metallic atoms,in other words,there have some localization bonds.For cluster Cr_5 or Cr_6,there have not only planar structures but also some stereoscopic structures,in which are mostly delocalization bonds.