A review of computational methods for electron affinity in determined molecules

Some density function theories ( DFT/ 6 - 311++ G (3 df, 3 pd ) basis set ) methods with as BPV86, B3PV91, B3LYP, LSDA, MPW1PW91, HCTH, THCTH, PBE1PBE, PBEPBE, and T PSSTPSS with Hartree– Fock (HF) and Ab initio methods. These calculations were at quadratic - complete basis set (CBS- Q method ). Results of these studies appear that DFT results overestimate and Hartree– Fock results underestimate of EA’s values as compared with experimental calculations. Good convergence with experimental studies of electron affinities in density functional theory methods. Electron affinities of LiBr, NaBr, F 2 and OH diatomic molecules have been calculated using methods above. The electron affinity values that have been extended using THCTH method are overvalued to OH and F2 compounds and dropped to NaBr and LiBr compounds. Also CBS-Q theory or method provides good calculations for OH, LiBr and NaBr molecules, therefore, the electron affinity result is lower than data in experiment one, by ( 1 eV) that in cases of F2 moelcule.