Density Functional Theory Research Method Of Hydrogen Bond Proton Migration

Hydrogen bonding is a unique non-covalent force with a certain degree of directionality and strength.The formation of hydrogen bonds is reproducible and highly reversible and is used to explain many biological,physical,chemical and material phenomena.Density functional theory(DFT)is inaccurate for intermolecular interactions without D3,D4 dispersion correction or NL non-local correction.DFT-D and DFT-NL methods such as B3LYP-D3 BJ,PBE0-D3 BJ,?B97X-V Methods such as DSD-BLYP-D3 BJ are more and more accurate for the calculation of intermolecular interactions;while strong hydrogen bonding systems are usually accompanied by different degrees of proton migration,both intermolecular interactions and chemical bond rupture and generation,general calculations The method cannot accurately describe the intermolecular interaction energy,which is a challenge to the theoretical calculation method.In this paper,35 pairs of complexes with obvious proton transfer characteristics.The geometry of the monomers and complexes is obtained in an MP2/aug-cc-p VTZ optimized configuration with minimal total energy.CCSD(T)/aug-cc-p VXZ(X=T,Q)extrapolated to obtain the "gold standard" CCSD(T)/CBS binding energy,and establish the benchmark set Proton transfer 35(referred to as PT35 benchmark set).The calculation method for the chemical accuracy of the root-mean-square deviation RMSD below 1 kcal/mol(binding energy)is high.DFT-D and DFT-NL calculate the PT35 reference set under the def2-QZVPPD basis set.Compared with the high-precision CCSD(T)/CBS,this paper preferentially recommends the non-local correction method ? B97M-V to calculate the system with proton transfer characteristics.Secondly,the comparison between the calculation amount and calculation accuracy of ? B97X-D and PBE0-2-D4 and PBE0-2,? B97X-D is recommended.Finally,PBE0-2-D4 and PBE0-2(Respectively,RMSD are 0.52,0.67,0.57,0.57 kcal/mol).The DFT-NL method has the highest accuracy in calculating the proton transfer system.The latest D4 correction does not significantly improve the calculation accuracy of the proposed system although the charge in the molecule is considered.The basis set superposition error BSSE of 40 DFT methods def2-QZVPPD is investigated.The BSSE of the double-hybrid functional is not negligible(BSSE0.48-1.67 kcal/mol),while the non-double hybrid functional can ignore the influence of BSSE(BSSE 0.05-0.41 kcal/mol).