Calculation of NMR chemical shifts using relativistic wave functions

使用相对论波函数计算 NMR 化学位移

• 批准号: 12640482
• 负责人: FUKUI Hiroyuki
• 金额: $ 2.18万
• 依托单位: Kitami Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640482/
• 关键词: Dirac equation; NMR; chemical shift; relativistic effect; DKH transformation

A two-component relativistic SCF perturbation theory, based on the Douglas-Kroll-Hess (DKH) transformation, was applied to the calculation of nuclear magnetic shielding tensors of hydrogen halides, HX (X=F, Cl, Br, I). Calculations were performed via the unrestricted coupled Hartree-Fock (CHF) scheme using gauge-including atomic orbitals (GIAOs) at four different levels. At the level I calculation, both the scalar relativistic (SR) and spin-orbit (SO) interactions were included in the zeroth-order Hamiltonian. However, the magnetic perturbation Hamiltonians were treated nonrelativistically. The results of these calculations indicated a large interplay between the SR and SO interactions. The level I calculation was found to be insufficient to explain the full relativistic effect on the halogen atom shielding. In order to reproduce the full relativistic effect, the mass-velocity effect on the magnetic perturbation Hamiltonians was introduced at the level II to IV calculations. Inclusion of the mass-velocity effects into all of the perturbation Hamiltonians, made at levels III and IV, improved the results greatly. The cross term between the nuclear attraction potential and the magnetic vector potential was introduced approximately in level IV. The level III calculation agreed most closely with the four-component relativistic random phase approximation (RPA) calculation by Visscher et al.

基于Douglas-Kroll-Hess（DKH）变换的双分量相对论SCF微扰理论，计算了卤化氢HX（X=F，Cl，Br，I）的核磁屏蔽张量.计算通过无限制耦合Hartree-Fock（CHF）计划使用规范，包括原子轨道（GIAO）在四个不同的水平。在第一级计算中，零级哈密顿量包含了标量相对论相互作用和自旋轨道相互作用。然而，磁微扰哈密顿量被非相对论地处理。这些计算的结果表明SR和SO相互作用之间的相互作用很大。水平I计算被认为是不足以解释完整的相对论效应的卤素原子屏蔽。为了再现完整的相对论效应，在II至IV级计算中引入了质量-速度效应对磁微扰哈密顿量的影响。将质量-速度效应纳入所有的微扰哈密顿量中，在第III和第IV级，大大改善了结果。在第四层近似地引入了核引力势与磁矢势之间的交叉项。III级计算与Visscher等人的四分量相对论无规相位近似（RPA）计算最接近。

项目成果

T. Baba, H. Fukui: "Calculation of nuclear magnetic shielding XIV. Relativistic mass-velocity corrected Perturbation Hamiltonian"Molecular Physics. Vol. 100, No. 5. 623-633 (2002)

T. Baba、H. Fukui：“核磁屏蔽计算 XIV。相对论质量速度校正扰动哈密顿量”分子物理学。

T.Baba, H.Fukui: "Calculation of nuclear magnetic shieldings XIV. Relativistic mass-velocity corrected perturbation Hamiltonians"Molecular Physics. Vol.100 No.5. 623-633 (2002)

T.Baba、H.Fukui：“核磁屏蔽计算 XIV。相对论质量速度校正扰动哈密顿量”分子物理学。

T.Baba, H.Fukui: "Calculation of nuclear magnetic shieldings XIV. Relativistic mass-velocity corrected perturbtion Hamiltoians"Molecular Physics. Vol.100 No.5. 623-633 (2002)

T.Baba、H.Fukui：“核磁屏蔽计算 XIV。相对论质量速度校正扰动哈密尔顿”分子物理学。