原子构造原理与过渡元素原子的价电子组态

Principles of Atomic Structure and the Valence Electron Configurations of the Transition Elements

According to the Aufoau build-up principle and the order of filling atomic orbits, the valence electron configuration of ground state atoms of the d-block transition elements seems only to be (n - 1 ) dx-2 us2(x here denotes the number of the electron in (n - 1 ) d and us orbits). But the result of the spectra test shows that the atomic electron structure of the d-block transition elements also has the configurations (n - 1 ) dx-1 ns1 and (n - 1 ) dx ns0. These two types of electron configurations are usually considered as "out of the ordinary". In addition, the another important phenomenon is that the electronic structure of the atoms for all of the elements can not attain the configuration (n - 1 ) d 6 ns1. The reasons why these exceptional electron configurations can be formed and why the configuration (n - 1 ) d 6 ns1 can not exist are not properly understood and at present no theory of the many-electron atom structure is entirely satisfactory[1-7]. For this, it seems that the theoretical difficulty lies in accounting for the diversification of electron configurations and for the non-existence of configuration (n - 1 ) d 6 ns1 as we did not pay more attention to the control effect of symmetry principle in atom structure. We know that the stability of a mass system depends on the mechanics conservation law in the system and each conservation law is always relative to the invariance of the certain symmetry. In atom structure, the main interaction is the electromagnetic interaction. So the stability of atom structure system must be bounded up with the symmetry of the electromagnetic interaction in the atom system. The direct expression of this interconnection is that, when the electrons are allotted to the orbits with energy equivalent or close to one another in many-electron atoms, they would always distribute themselves in such a way that there is a relative highest symmetry configuration. That is to say, the way of the distribution of electrons(include electron spin states) in orbits is limited not only by the energy of orbits but also by the symmetry of the electron configuration. Therefore, this leads to the diversification of the electron configuration of d- and f-blocks elements and the experiment fact pointed out by Hund’s first rule. We call the connection between the atom structure and symmetry"rule of electron configuration symmetry of atomic structure" or "symmetry principle of atomic structure". In this paper the discussion of the control effect of symmetry principle in atomic structure has been given in detail.