Errors of the most popular functionals in the calculation of the electron energy and enthalpy of formation of compounds

The calculation of the total electron energy E_total and the enthalpy of formation ${{\rm{\Delta }}}_{f}{H}_{298}^{0}$ of the compounds GeO₂, C₂H₆, NH₂CHO, C₆H₆, C₅H₅N and C₆H₄O₂ has been performed using methods B1LYP, B1PW91, B3LYP, BHandH, BHandHLYP, BLYP, BP, CAMY-B3LYP, HTBS, KMLYP, LCY-BLYP, LCY-BP86, LCY-PBE, LDA, M06, M06-2X, M06-HF, M06L, mPBE, mPW, MPW1K, MPW1PW, O3LYP, OLYP, OPBE, OPBE0, PBE, PBE0, PBEsol, PW91, revPBE, revTPSS, RPBE, TPSS, TPSSH, X3LYP and HF in the slater basis QZ4P, aug-TZ2P and TZ2P, as well as DZ, and the errors of calculation of E_total and Δ ${{\rm{\Delta }}}_{f}{H}_{298}^{0}$ at the variation limit were determined. The QZ4P basis set and the settings of the ADF program were configured so that these errors can be attributed to the structure of DFT functionals. The dependence of the E_total and ${{\rm{\Delta }}}_{f}{H}_{298}^{0}$ based on type (size) of the basis set was studied. It has been demonstrated that the functional M06 has the smallest error independent from the incomplete basis set, and the optimal combinations are DFT/TZ2P, where DFT = OPBE, X3LYP, B3LYP, revTPSS, M06L, M06, TPSS, CAMY-B3LYP.