BEYOND THE MNDO MODEL - METHODICAL CONSIDERATIONS AND NUMERICAL RESULTS
BEYOND THE MNDO MODEL - METHODICAL CONSIDERATIONS AND NUMERICAL RESULTS
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DOI：
10.1002/jcc.540140704
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发表时间：
1993-07-01
影响因子：
3
通讯作者：
THIEL, W
中科院分区：
文献类型：
--
作者：
KOLB, M;THIEL, W
建议通过在核心哈密顿矩阵的单中心部分明确包含价壳层正交化修正、穿透积分和有效核心势（ECP）来改进MNDO模型。由解析公式和数值从头算结果的指导下，正交化校正表示的共振积分，由一个新的经验参数函数表示。所有的两个中心的库仑相互作用和ECP积分的分析评估高斯的基础上，然后由一个统一的Klopman-Ohno标度。描述了所提出的NDDO SCF方法的一个特定实现，并针对元素H、C、N、O和F进行参数化。在基态属性的统计评估中，该实现显示出比MNDO、AMI和PM 3略微但一致的改进。显着的改善被发现的激发态，过渡态，和强氢键。目前的实施可能的进一步增强进行了讨论。
It is suggested to improve the MNDO model by the explicit inclusion of valence-shell orthogonalization corrections, penetration integrals, and effective core potentials (ECPs) in the one-center part of the core Hamiltonian matrix. Guided by analytic formulas and numerical ab initio results, the orthogonalization corrections are expressed in terms of the resonance integrals that are represented by a new empirical parametric function. All two-center Coulomb interactions and ECP integrals are evaluated analytically in a Gaussian basis followed by a uniform Klopman-Ohno scaling. One particular implementation of the proposed NDDO SCF approach is described and parameterized for the elements H, C, N, O, and F. In a statistical evaluation of ground-state properties, this implementation shows slight but consistent improvements over MNDO, AMI, and PM3. Significant improvements are found for excited states, transition states, and strong hydrogen bonds. Possible further enhancements of the current implementation are discussed.