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文献[1]中,在局域密度泛函近似(LDA)的基础上,通过自相关校正(SIC)和自旋平行相关扣除(SPCC),我们提出了估算多电子体系电子相关能的改进电子气方案(MEGA),对大多数中性原子、分子体系给出了相当准确的电子相关能,相对误差分别在5%,10%以内.但尚有一些不足之处.由于视Hartree-Fock(HF)极限能量包含全部自旋平行电子间的相关能,MEGA过多地进行了自旋平行相关扣除;同时因没有考虑实际体系电子密度的“非均匀性”造成的梯度效应,LDA(即零级梯度近似)又高估了相关能.对大多数中性原子和分子,正负
In [1], based on the local density functional approximation (LDA), we propose a modified electron to estimate the electron-related energy of the multi-electron system through the correlation correction (SIC) and the spin-spin correlation subtraction Gas program (MEGA) gives quite accurate electron-related energy for most neutral atoms and molecular systems with relative errors of 5% and 10%, respectively, but there are still some shortcomings. Due to the Hartree-Fock HF), the ultimate energy contains the correlation energies of all the spin-parallel electrons, and MEGA carries out spin-spin correlation deduction excessively. At the same time, due to the gradient effect caused by “inhomogeneity” of the actual system electron density, the LDA Level gradient approximation) overestimates the correlation energy, positive and negative for most neutral atoms and molecules