提出一种改进的ZORA(Zeroth-Order Regular Approximation to the Dirac Equation)方法,其单电子方程为:[σ·p(c^2/(2c^2-V_0))σ·p+V(r)]Ψ=εΨ式中VO为空间限域的势能函数:V_0(r=sum from A to(V_0~A(r_A)),r_A=|r-R_A|,V_...
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提出一种改进的ZORA(Zeroth-Order Regular Approximation to the Dirac Equation)方法,其单电子方程为:[σ·p(c^2/(2c^2-V_0))σ·p+V(r)]Ψ=εΨ式中VO为空间限域的势能函数:V_0(r=sum from A to(V_0~A(r_A)),r_A=|r-R_A|,V_0~A(r_A)=V^A(r_A{1+exp[α(r_A-r_0~A)]}^(-1)其中A表示分子的某个组成原子,R_A为A原子的位置矢量,V^A(r_A)为自由A原子的势函数,α和r_0~A为参数.改进的ZORA方法具有原来方法的所有优点,避免了原有ZORA方法因不满足标度变换不变性带来的缺陷,而且计算过程简单.具体计算表明,通过适当选择参数α和r_0~A,用本研究提出来的方法,在计算分子几何结构和键合能时,基本上消除了ZORA方法由于标度变换依赖性产生的误差.
Magnetic coupling constants J for the complete structures of rare earth\|transition metal compounds:LGdCu(NO\-3)\-3·Me\-2CO(1,Gd(Ⅲ)Cu(Ⅱ)) and [Ce(C\-4H\-7ON)\-4(H\-2O)\-3][Cr(CN)\-6]·2H\-2O(2, Ce(Ⅲ)Cr(Ⅲ)...
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Magnetic coupling constants J for the complete structures of rare earth\|transition metal compounds:LGdCu(NO\-3)\-3·Me\-2CO(1,Gd(Ⅲ)Cu(Ⅱ)) and [Ce(C\-4H\-7ON)\-4(H\-2O)\-3][Cr(CN)\-6]·2H\-2O(2, Ce(Ⅲ)Cr(Ⅲ)) have been calculated by the combination of the broken\|symmetry approach with the spin project method under the DFT *** J value for 1 is a small number in absolute value -2 4cm -1 for calculation,3 5cm -1 for experimental *** spin density distributions are in detail discussed on the basis of Mulliken population analysis,taking into account the coexistence of spin delocalization and spin polarization *** 1,the spin distribution in the ground state may be understood as a result of the competition between two mechanisms:a spin delocalization from Cu(Ⅱ) and a spin polarization of Gd(Ⅲ),and the former is *** the case of 2,both transition metal Cr(Ⅲ) and rare earth Ce(Ⅲ) display a spin polarization effect on the surrounding atoms,where a counteraction of the opposite polarization effects leads a low spin density on the bridging ligand *** the ground state of 2,the stronger polarization effect of Cr(Ⅲ) even causes the positive spin density on the adjacent bridging atom N1.
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