First principles study of the evolution of the properties of neutral and charged phosphorus clusters

Abstract

Geometrical and electronic properties of P n ( n=2–15) neutrals, cations and anions have been investigated using the density functional method of B3LYP. Berny structural optimization and frequency analyses are performed with the basis of 6-311G(d) for both neutrals and charged ions. The total energies of these clusters are used to study the evolution of their binding energy, relative stability, ionization potentials, and electron affinities as a function of size. The geometrical changes are accompanied by corresponding changes in the coordination number. The stability of clusters exhibits strong even–odd alternations with several magic numbers. The neutral P n clusters are found to be even-numbered with local maxima at n=2, 4, and 14, while the cationic and anionic clusters are preferentially odd-numbered with P 2 +, P 3 +, P 2 −, P 5 − and P 15 − being the most stable ions. The calculated results agree very well with all available experimental data on ionization potentials and electron affinities. Frequency analyses indicate that the previously proposed as the ground-state structure of P 8 −, P 9 and P 11 +, is in fact a first-order stationary point with an imaginary frequency at 216i, 81i and 118i cm −1, respectively.