Calculation of the inner‐shell contribution to the correlation energy through DLPNO‐CEPA/1 and scaled same‐spin second‐order Møller–Plesset perturbation theory

2020 ◽  
Vol 41 (10) ◽  
pp. 1012-1017
Author(s):  
Hernán R. Sánchez
Keyword(s):  
Perturbation Theory ◽  
Correlation Energy ◽  
Second Order ◽  
Moller Plesset ◽  
Plesset Perturbation Theory

scholarly journals Spin-component-scaled and dispersion-corrected second-order Møller-Plesset perturbation theory: A path toward chemical accuracy

2021 ◽  
Author(s):  
Chandler Greenwell ◽  
Jan Rezac ◽  
Gregory Beran
Keyword(s):  
Perturbation Theory ◽  
Density Functional ◽  
Correlation Energy ◽  
Computational Cost ◽  
Second Order ◽  
Spin Component ◽  
Dispersion Interactions ◽  
Reaction Energies ◽  
Moller Plesset ◽  
Plesset Perturbation Theory

Second-order Møller-Plesset perturbation theory (MP2) provides a valuable alternative to density functional theory for modeing problems in organic and biological chemistry. However, MP2 suffers from known lim- itations in the description of van der Waals dispersion interactions and reaction thermochemistry. Here, a spin-component-scaled, dispersion-corrected MP2 model (SCS-MP2D) is proposed that addresses these weaknesses. The dispersion correction, which is based on Grimme’s D3 formalism, replaces the uncoupled Hartree-Fock dispersion inherent in MP2 with a more robust coupled Kohn-Sham treatment. The spin- component scaling of the residual MP2 correlation energy then reduces the remaining errors in the model. This two-part correction strategy solves the problem found in earlier spin-component-scaled MP2 models where completely different spin-scaling parameters were needed for describing reaction energies versus in- termolecular interactions. Results on 18 benchmark data sets and two challenging potential energy curves demonstrate that SCS-MP2D considerably improves upon the accuracy of MP2 for intermolecular interac- tions, conformational energies, and reaction energies. Its accuracy and computational cost are competitive with state-of-the-art density functionals such as DSD-BLYP-D3(BJ), revDSD-PBEP86-D3(BJ), ωB97X-V, and ωB97M-V for systems with ∼100 atoms.

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