• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Subshell fitting of relativistic atomic core electron densities for use in QTAIM analyses of ECP-based wave functions
【24h】

Subshell fitting of relativistic atomic core electron densities for use in QTAIM analyses of ECP-based wave functions

机译：相对论原子核电子密度的子壳拟合，用于基于ECP的波函数的QTAIM分析

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Scalar-relativistic, all-electron density functional theory (DFT) calculations were done for free, neutral atoms of all elements of the periodic table using the universal Gaussian basis set. Each core, closed-subshell contribution to a total atomic electron density distribution was separately fitted to a spherical electron density function: a linear combination of s-type Gaussian functions. The resulting core subshell electron densities are useful for systematically and compactly approximating total core electron densities of atoms in molecules, for any atomic core defined in terms of closed subshells. When used to augment the electron density from a wave function based on a calculation using effective core potentials (ECPs) in the Hamiltonian, the atomic core electron densities are sufficient to restore the otherwise-absent electron density maxima at the nuclear positions and eliminate spurious critical points in the neighborhood of the atom, thus enabling quantum theory of atoms in molecules (QTAIM) analyses to be done in the neighborhoods of atoms for which ECPs were used. Comparison of results from QTAIM analyses with all-electron, relativistic and nonrelativistic molecular wave functions validates the use of the atomic core electron densities for augmenting electron densities from ECP-based wave functions. For an atom in a molecule for which a small-core or medium-core ECPs is used, simply representing the core using a simplistic, tightly localized electron density function is actually sufficient to obtain a correct electron density topology and perform QTAIM analyses to obtain at least semiquantitatively meaningful results, but this is often not true when a large-core ECP is used. Comparison of QTAIM results from augmenting ECP-based molecular wave functions with the realistic atomic core electron densities presented here versus augmenting with the limiting case of tight core densities may be useful for diagnosing the reliability of large-core ECP models in particular cases. For molecules containing atoms of any elements of the periodic table, the production of extended wave function files that include the appropriate atomic core densities for ECP-based calculations, and the use of these wave functions for QTAIM analyses, has been automated.
机译：使用通用高斯基集对元素周期表中所有元素的自由中性原子进行了标量相对论全电子密度泛函理论（DFT）计算。每个核，闭合子壳对总原子电子密度分布的贡献分别拟合为球形电子密度函数：s型高斯函数的线性组合。对于以封闭子壳定义的任何原子核，所得的核子壳电子密度可用于系统且紧凑地逼近分子中原子的总核电子密度。当使用基于哈密顿量的有效核电势（ECP）的计算从波函数增加电子密度时，原子核电子密度足以恢复核位置上否则存在的电子密度最大值并消除杂散临界原子附近的原子点，因此可以在使用ECP的原子附近进行分子中的原子量子理论（QTAIM）分析。将QTAIM分析的结果与全电子，相对论和非相对论分子波函数进行比较，验证了使用原子核电子密度来增强基于ECP的波函数的电子密度。对于使用小核或中核ECP的分子中的原子，使用简单的，紧密定位的电子密度函数简单地表示核实际上实际上足以获得正确的电子密度拓扑并执行QTAIM分析以获得最少的半定量有意义的结果，但这在使用大核ECP时通常不正确。比较QTAIM结果（通过在此处提供的实际原子核电子密度来增强基于ECP的分子波函数与在紧密核密度的极限情况下进行增强而得到的QTAIM结果），对于在特定情况下诊断大核ECP模型的可靠性可能是有用的。对于包含元素周期表中任何元素原子的分子，扩展波函数文件的生成（包括用于基于ECP的计算的适当原子核密度）以及这些波函数在QTAIM分析中的使用已实现了自动化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号