Basis Set Orbital Relaxation in Atomic and Molecular Hydrogen Systems
Basis Set Orbital Relaxation in Atomic and Molecular Hydrogen Systems
复制标题
原子和分子氢系统中的基组轨道弛豫
DOI：
10.1007/s10947-005-0080-z
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发表时间：
2004
影响因子：
0.8
通讯作者：
V. Belousov
中科院分区：
文献类型：
--
作者：
A. Ermakov;A. E. Merkulov;A. A. Svechnikova;V. Belousov
轨道弛豫（OR）相当于氢分子和离子的轨道指数相对于孤立原子的指数的变化；它被表示为一中心和二中心贡献的总和，具体取决于有效原子电荷和分子中其他原子的存在。分离指数贡献的过程包括在一组特殊的中性和带电原子和分子中处理氢的 OR ，这些原子和分子具有一定的电子态多重性。在自旋无限制的Hartree-Fock方法的框架内，我们使用最小分裂价壳基组、包含极化函数的基组和分组自然轨道的扩展组发现并讨论了氢原子和分子基轨道指数的最佳值。建议为 OR 使用一个简单的能量模型。导出了用于评估含氢系统中松弛轨道指数的表达式。
Orbital relaxation (OR) amounts to variation of the orbital exponents in hydrogen molecules and ions relative to the exponents of the isolated atom; it is represented as the sum of the one- and two-center contributions depending on the effective atomic charge and on the presence of other atoms in the molecule. The procedure for isolating the contributions of the exponent includes treatment of the OR of hydrogen in a special set of neutral and charged atoms and molecules with certain multiplicities of their electronic states. Within the framework of the spin-unrestricted Hartree-Fock method, we found and discussed the optimal values of the exponents of the basis orbitals of hydrogen atoms and molecules using the minimal split valence-shell basis set, the basis set that includes the polarization function, and the expanded set of grouped natural orbitals. A simple energy model is suggested for OR. Expressions are derived for evaluating the exponents of the relaxed orbitals in hydrogen-containing systems.