The phosphorus clusters Pn (n=1-6) and their anions: Structures and electron affinities

The molecular structures and electron affinities of the Pn/Pn− (n=1-6) species have been examined using seven density functional theory (DFT) methods. The basis sets used in this work is of double-ζ plus polarization quality with additional diffuse s- and p-type functions, denoted DZP++. The geometries are fully optimized with each DFT method independently. According to the total energies, the most stable isomers have been predicted. Then, the adiabatic electron affinity (EAad), the vertical electron affinity (EAvert), and the vertical detachment energy (VDE) were reported. The most reliable adiabatic electron affinities, obtained at the DZP++ BLYP level of theory, are 0.83 (P), 0.61 (P2), 1.57 (P3), 0.47 (P4), 4.03 eV (P5) and 2.05 (P6), respectively. These EAad values for P, P2 and P3 are in very good agreement with experimental values (average absolute error 0.06 eV). The most reliable VDE, obtained at the DZP++ BLYP level of theory, are 0.73 (P2−), 2.18 (P3−), 1.70 (P4−), 4.10 eV (P5−) and 2.19 (P6−), respectively. These values are in good agreement with experimental values (average absolute error 0.12 eV with P3− excluded).