title: Assessment of the performance of MP2 and MP2 variants for the treatment of noncovalent interactions.
abstract: For many years, MP2 served as the principal method for the treatment of noncovalent interactions. Until recently, this was the only technique that could be used to produce reasonably accurate binding energies, with binding energy errors generally below ~35%, at a reasonable computational cost. The past decade has seen the development of many new methods with improved performance for noncovalent interactions, several of which are based on MP2. Here, we assess the performance of MP2, LMP2, MP2-F12, and LMP2-F12, as well as spin component scaled variants (SCS) of these methods, in terms of their abilities to produce accurate interaction energies for binding motifs commonly found in organic and biomolecular systems. Reference data from the newly developed S66 database of interaction energies are used for this assessment, and a further set of 38 complexes is used as a test set for SCS methods developed herein. The strongly basis set-dependent nature of MP2 is confirmed in this study, with the SCS technique greatly reducing this behavior. It is found in this work that the spin component scaling technique can effectively be used to dramatically improve the performance of MP2 and MP2 variants, with overall errors being reduced by factors of about 1.5-2. SCS versions of all MP2 variants tested here are shown to give similarly accurate overall results.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Czech Republic. kev.e.riley@gmail.com
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Riley
authors.forename: James A
authors.initials: JA
authors.lastname: Platts
authors.forename: Jan
authors.initials: J
authors.lastname: Řezáč
authors.forename: Pavel
authors.initials: P
authors.lastname: Hobza
authors.forename: J Grant
authors.initials: JG
authors.lastname: Hill
mesh_terms: D011789:Quantum Theory; D013816:Thermodynamics