Performance of Møller-Plesset second-order perturbation theory and density functional theory in predicting the interaction between stannylenes and aromatic molecules.

Sławomir Wojtulewski,Piotr Matczak

doi:10.1007/s00894-015-2589-1

Abstract

The performances of Møller-Plesset second-order perturbation theory (MP2) and density functional theory (DFT) have been assessed for the purposes of investigating the interaction between stannylenes and aromatic molecules. The complexes between SnX2 (where X = H, F, Cl, Br, and I) and benzene or pyridine are considered. Structural and energetic properties of such complexes are calculated using six MP2-type and 14 DFT methods. The assessment of the above-mentioned methods is based on the comparison of the structures and interaction energies predicted by these methods with reference computational data. A very detailed analysis of the performances of the MP2-type and DFT methods is carried out for two complexes, namely SnH2-benzene and SnH2-pyridine. Of the MP2-type methods, the reference structure of SnH2-benzene is reproduced best by SOS-MP2, whereas SCS-MP2 is capable of mimicking the reference structure of SnH2-pyridine with the greatest accuracy. The latter method performs best in predicting the interaction energy between SnH2 and benzene or pyridine. Among the DFT methods, ωB97X provides the structures and interaction energies of the SnH2-benzene and SnH2-pyridine complexes with good accuracy. However, this density functional is not as effective in reproducing the reference data for the two complexes as the best performing MP2-type methods. Next, the DFT methods are evaluated using the full test set of SnX2-benzene and SnX2-pyridine complexes. It is found that the range-separated hybrid or dispersion-corrected density functionals should be used for describing the interaction in such complexes with reasonable accuracy.Electronic supplementary materialThe online version of this article (doi:10.1007/s00894-015-2589-1) contains supplementary material, which is available to authorized users.

Highlights

Quantum-chemical modeling of organometallic systems and inorganic systems containing metal atoms is a challenging task because of the large number of electrons and strong electron correlation effects occurring in metal atoms
We start with assessing the performance of six MP2-type methods in predicting the geometries of two stannylenearomatic molecule complexes
As no experimental characterization of the geometries of these complexes exists, we used the geometries optimized with the CCSD method as references for the assessment of the MP2-type methods

Summary

Introduction

Quantum-chemical modeling of organometallic systems and inorganic systems containing metal atoms is a challenging task because of the large number of electrons and strong electron correlation effects occurring in metal atoms. DFT methods are able to include a large fraction of electron correlation and their computational cost scales favorably with the size of molecular systems (formally between O(N3) and O(N4), where N is proportional to system size). DFT methods suffer from the spurious self-interaction of electrons, which results in too much electron delocalization and too low total energies [3, 4] Another weakness is their inability to describe long-range electron correlations that are responsible for dispersive forces [1]. Some reduction in the self-interaction can be provided by the inclusion of either the long-range correction or a substantial, global portion of

Methods

Results

Conclusion