Hartree—Fock与密度泛函混合处理中的电子自相关和自旋平行相关问题

Self- Correlation and Spin - Parallel Correlation in the Hybrid Approach of Hartree - Fock and Density Functional Theory

电子气近似中的电子相关能与量子化学中的Hartree-Fock相关能在定义上不相互等同 作者从假想的、含N个电子的“有限电子气”出发,通过比较这类体系与无限电子气在物理模型上的差异,合理地把电子气相关能定量地分解为单电子自相关、电子自旋平行相关以及Hartree-Fock相关三个部分,并阐明了各组分的构成随N的变化规律在此基础上建立的Hartree-Fock与密函混合处理方案,无须借助任何经验参数,仅通过简捷的计算即可实现原子和分子的相关能校正平均误差为4.2%,优于CI—SD和MP_4等Hartree—Fock处理的结果.

The definition of correlation energy in Electron Gas Approximation (EGA) is not equivalent to that in Hartree -Fock framework. By comparing the physical model of the infinite electron gas with that of the proposed finite electron gas, which comprises finite number of electrons, the EGA correlation energy has been divided into three parts: self - correlation within one electron, spin - parallel correlation and Hartree - Fock correlation. The dependence of the contribution from each component on the electron number (N) has been described. The method of hybrid of Hartree - Fock and Density Functional Theory, generated from the above analysis, can be used to estimate the correlation energy of atoms and molecules without employing any empirical parameter. The average error of the calculation 4. 2% is lower than those by conventional post Hartree-Fock methods, such as CI-SD and MP4.