Accurate Thermochemistry for Large Molecules with Modern Density Functionals

摘要: The thermodynamic properties of molecules are fundamental interest in chemistry and engineering. This chapter deals with developments made the last few years search for accurate density functional theory-based quantum chemical electronic structure methods this purpose. typical target accuracy reaction energies larger systems condensed phase is realistically about 2 kcal/mol. level within reach modern approximations when combined appropriate continuum solvation models slightly modified thermostatistical corrections. Nine higher-level functionals dispersion corrected hybrid, range-separated double-hybrid type were first tested on four common, mostly small molecule, thermochemical benchmark sets. These results complemented by large molecule examples. In these 70–200 atoms, long-range electron correlation responsible important parts interactions dispersion-uncorrected fail badly. When used together properly polarized triple- or quadruple-zeta AO basis sets, most investigated provide gas close to values estimated from experiment. use theoretical back-correction schemes thermal effects, impact self-interaction error unsaturated systems, prospect local coupled-cluster based reference as benchmarks discussed.