Accurate prediction of nuclear magnetic resonance shielding constants: An extension of the focal-point analysis method for magnetic parameter calculations (FPA-M) with improved efficiency

作者：Wang, Kangli; Sun, Meng; Cui, Deng; Shen, Tonghao; Wu, Anan^*; Xu, Xin^*

来源：Journal of Chemical Physics, 2018, 149(18): 184101.

DOI：10.1063/1.5041979

• GAUSSIAN-BASIS SETS
• CORRELATED MOLECULAR CALCULATIONS
• PLESSET PERTURBATION-THEORY
• COUPLED-CLUSTER SINGLES
• EXTENDED ONIOM METHOD
• CONSISTENT BASIS-SETS
• C-13 CHEMICAL-SHIFTS
• GAS-PHASE
• POLARIZATION-CONSISTENT
• 2ND DERIVATIVES

Previously, we have proposed a method, FPA-M, for focal-point analysis of magnetic parameter calculations [Sun et al., J. Chem. Phys. 138, 124113 (2013)], where the shielding constants at equilibrium geometries sigma(e) are calculated with the second order Moller-Plesset perturbation (MP2) approach, which are extrapolated to the complete basis set (CBS) limit and then augmented by the [sigma(e)(CCSD(T)) - sigma(e)(MP2)] difference at a valence triple-zeta (VTZ) basis set, where CCSD(T) stands for the coupled cluster singles and doubles model with a perturbative correction for triple excitations. This FPA-M(MP2) method provides satisfactory results to approach to the corresponding CCSD(T)/CBS values for elements of the first two rows in the periodic tables. A series of extensions have been explored here, which replace the MP2/CBS with the Hartree-Fock (HF)/CBS for efficiency. In particular, the [sigma(e)(CCSD(T)) - sigma(e)(MP2)] VTZ difference is replaced by a step-wise correction from the [sigma(e)(CCSD(T)) - sigma(e)(MP2)] difference at a valence double-zeta basis set plus the [sigma(e)(MP2) - sigma(e)(HF)] VTZ difference, leading to a new scheme, denoted here as FPA-M(HF 0). A systematical comparison has demonstrated that the FPA-M(HF 0) method provides an excellent balance between accuracy and efficiency, which makes routinely accurate calculations of the shielding constants for medium-sized organic molecules and biomolecules feasible. Published by AIP Publishing.

• 出版日期2018-11-14
• 单位厦门大学; 复旦大学