A density functional theory study of the anthracene anion

The optimized geometries, harmonic vibrational frequencies, and absolute en ergies of anthracene and anthracene(-) were determined using density functi onal methods. Adiabatic electron affinities (EAs) of 0.360, 0.274, 0.590 an d 0.530 eV were calculated using B3LYP/cc-pVDZ, BLYP/cc-pVDZ, BP86/cc-pVDZ and B3LYP/6-31+G*, respectively. The EAs are in good agreement with experim ent, with the B3LYP/6-31+G* value matching the experimental value and the B P86/cc-pVDZ value displaying an absolute error of only 0.060 eV. Accurate p redictions of experimental parameters were obtained using all three functio nals. Single point calculations using the aug-cc-pVDZ, cc-pVTZ and aug-cc-p VTZ basis sets are included to investigate the effect of basis set expansio n and diffuse functions on the computed EAs. The excellent performance of d ensity functional theory (DFT) for this system contrasts with poor results generated using Hartree-Fock theory. (C) 2000 Elsevier Science B.V. All rig hts reserved.