Orbital-optimized third-order Møller-Plesset perturbation theory and its spin-component and spin-opposite scaled variants: Application to symmetry breaking problems

2011 ◽  
Vol 135 (22) ◽  
pp. 224103 ◽  
Author(s):  
Uğur Bozkaya
Keyword(s):  
Perturbation Theory ◽  
Symmetry Breaking ◽  
Spin Component ◽  
Third Order ◽  
Moller Plesset ◽  
Plesset Perturbation Theory

Microsolvation of the formic acid dimer — (HCOOH)2(H2O)n clusters with n = 1, . . ., 5

2010 ◽  
Vol 88 (8) ◽  
pp. 736-743 ◽  
Author(s):  
Cara M. Nordstrom ◽  
Alaina J. McGrath ◽  
Ajit J. Thakkar
Keyword(s):  
Density Functional Theory ◽  
Perturbation Theory ◽  
Hydrogen Bonds ◽  
Formic Acid ◽  
Density Functional ◽  
Water Molecules ◽  
Spin Component ◽  
Functional Theory ◽  
Moller Plesset ◽  
Plesset Perturbation Theory

Density functional theory and spin-component-scaled Møller–Plesset perturbation theory calculations are used to examine the microsolvation of the formic acid dimer. The lowest energy structures with n water molecules consist of a n-water cluster, not necessarily of lowest energy, with two formic acid molecules attached to its surface by hydrogen bonds. The total number of hydrogen bonds does not correlate directly with relative stability.

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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