HFR方程初始波函数的挑选

The Choice of an Initial Guess Wave Function of HFR Eq.

找出一个好的初始波函数对DSCF更显得重要。对闭壳层提出一个方程SB—SCE=0。若基i,j属于不同原子,(SB)_(ij),=S_(ij);若基i,j属于同一原子,(SB)_(ij)=0。S_(ij)为重迭矩阵元。该方程的前OCC个最大本征值对应于占有轨道。由此构出初始波函数。以STO-nG为基,计算了22个分子,采用自然迭代均能快速收敛。

It is important for DSCF to find a good initial guess wave function. An Eq. SB—SCE=0 has been proposed for a closed shell system, whereSB_(ij)=S_(ij) if i and j are at fifferent atomsSB_(ij)=0 if i and j are at the same atom.The S_(ij) is an overlap matrix element. The occ highest roots of the Eq. corresPond to the occupied MOs. Thus, initial guess wave functions are constructed. Twenty two compounds are calculated with STO-nG basis set. Convergences are rapid with natural iteration.