Using the random matrix theory,we calculate the spin susceptibility of metallic nano-particles with the energy level spaceings conforming to the Gauss Orthogonal Ensemble and Gauss Symplectic Ensemble distribution respectively,and find that the spin susceptibility of an ensemble of metallic nano-particles are affected by the effect of level statistics and the electron number parity(odd or even).

The static paths approximation (SPA) method is used to calculate the spin susceptibility of small superconducting particles in grand canonical ensemble, with a treatment that properly takes into account the effects of thermal fluctuations and level statistics.

As the estimate of paramagnetic susceptibility of free electron in metal, the specific heat and the conductivity of free electron in metal can be also estimated by Pauli exclusion principle.

In this paper,we have introduced calculated method and the process of deal with microcomputer for absorption spectra,the ZFS,EPR parameters of the ground state,the Schottky low-temperature heatcapacity,and the paramagnetic susceptibility of Ni(pz) 4Cl 2 complex,using complete configuration mixing unified crystal field theory for d 8[(1-C 2)D * 4h +C 2D * 2h ] .

By means of a complete configuration mixing unified crystal field theory for d~8(D_(4h)~*),the optical spectra,the ground state ZFS,EPS parameters,the ground state paramagnetic susceptibility and the magnetization of the Ni(mpz)_4Cl_2 compounds are analysed and calculated systematically.