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通过分析从头计算中不同基函数的作用, 提出一种经济有效的基函数选取方案. 依照该方案, 基函数的选取应考虑体系中不同原子的性质及实际的化学环境. 描述一般体系时可根据该原子在元素周期表中的位置从左向右依次增加基函数用量. 对荷负电原子, 则使用更多的基函数以及适当的极化函数或弥散函数. 对荷正电原子, 基函数的用量可适当减少. 对正常价态的饱和共价键合原子不需加极化或弥散函数, 对氢键、弱相互作用体系、官能团及零价或低价金属原子等敏感体系则需加极化或弥散函数. 据此, 可在适中基函数和能承受的计算量下得到具有相当可靠性的计算结果. 对一系列体系计算分析充分证明, 该方案是非常实用和有效的. 此方案可适用于Hartree-Fock, Mfller-Plesset和密度泛函等计算中, 并对化学、材料科学和生命科学研 究广泛的大体系计算具有重要的实际应用.
By analyzing the function of different basis functions in ab initio calculation, a cost-effective basis function selection scheme is proposed. According to this scheme, the selection of basis functions should take into account the properties of different atoms in the system and the actual chemical environment. The atoms in the periodic table position from left to right in turn increase the amount of basis function. For negatively charged atoms, the use of more basis functions and appropriate polarization or dispersion function. For positive charge atoms, basis functions The amount can be properly reduced.For the normal valences of saturated covalent bond atoms do not need to add polarization or dispersion function, hydrogen bonds, weak interaction system, functional groups and zero or low-priced metal atoms and other sensitive systems need to add very Or dispersion function .According to this, we can get a fairly reliable calculation results under the moderate basis function and the amount of calculation that can be supported.Calculation and analysis of a series of systems have proved that the scheme is very practical and effective. Suitable for calculations such as Hartree-Fock, Mfller-Plesset, and density functional calculations, and is important for a broad system of calculations in chemistry, materials science, and life sciences The practical application.