范德华作用的量子化学研究(二)

Quantum Chemical Study of the Role of the van der Waals Interaction (2)

摘要: 本文通过用量子化学耦合簇CCSD/aug-cc-pVTz方法，对稀有气体二聚体He-He的键长进行了扫描，对键长变化过程中的每个点作了电子密度差及图形，通过这连贯变化的图形，解读了范德华作用的本质和形成机理。当He-He逐渐缩短距离时，配对的电子云球相碰。由于Pauli互斥，电子云球变形，形成了电子一定程度的回避，同时产生了一定程度的电子共享，达到吸引和排斥的平衡，从而构成了范德华力。整个过程用动画生动地展示出来了。 In this paper, coupled-cluster CCSD/aug-cc-pVTz and related quantum chemistry methods are employed to perform He-He bond length scan for helium dimer and to obtain the electron density differences and figures for all of the points in the variation process of the bond length; the nature and formation mechanism of van der Waals interaction are interpreted by contiguously changing graphics. When the distance between helium atoms becomes short, paired electron cloud collide. Due to Pauli repulsion, electron cloud balls deform, forming a certain degree of electron avoid- ance as well as electron sharing, and then the van der Waals force is formed due to the equilibrium between the attract- tion and repulsion. The whole process is vividly presented by the animation.