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

Abstract

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.

How many more polymorphs of ROY remain undiscovered

“… 71 These corrections replace the B86bPBE-XDM intramolecular conformational energy with one computed from spin-component-scaled dispersion-corrected second-order Møller–Plesset perturbation theory (SCS-MP2D) at the complete-basis-set limit. 100 This model reproduces benchmark coupled cluster theory conformational energies of ROY well (Fig. S3 † ) at modest computational cost.…”

Non-Covalent Interactions Atlas Benchmark Data Sets 5: London Dispersion in an Extended Chemical Space

“…This observation had been rationalized down to the properties of uncoupled Hartree-Fock dispersion, 71 which was also exploited in several attempts to correct this behaviour. [72][73][74][75] Another, more empirical approach to correcting the interaction energies is scaling the spin components of the MP2 correlation energy in SCS-MP2 and SCS-MI-MP2 methods. 76,77 The results obtained in the whole D1200 data set are in line with previous findings; the errors of MP2 are rather large, and neither SCS-MP2 nor SCS-MI-MP2 addresses this problem satisfactorily when compared to e.g.…”

“…74 SCS-MP2D then extends this model by scaling the spin components of the MP2 correlation energy. 75 The results are listed along with uncorrected MP2 in Table 3. Both of these approaches work very well in hydrocarbons, reducing the error in π -π interactions from 43 to about 6 %.…”

Appraisal of dispersion damping functions for the effective fragment potential method

“…19,20 The HF case is interesting insofar as dispersion-corrected HF theory does not involve any double-counting of electron correlation effects in the "middle-range" region, corresponding to non-bonded close-contact distances in van der Waals complexes, which is a concern in dispersioncorrected DFT. 17,[21][22][23] Empirical dispersion corrections have also been introduced in the context of second-order Møller-Plesset perturbation theory (MP2), 24,25 because while MP2 does provide a first-principles description of dispersion, it is not a quantitative method for that purpose. [25][26][27][28][29][30][31][32] Dispersion corrections have also been introduced for the closely-related method of symmetryadapted perturbation theory (SAPT).…”