Lowest-energy structures and photoelectron spectra of InnPn (n = 1-12) clusters from density functional theory

Lowest-energy structures of InnPn (n = 1-12) clusters have been determined from a number of structural isomers using all-electron density functional calculations. The In-P alternating hollow cage-like structures emerge at n = 7. Size-dependent cluster properties such as binding energy, HOMO-LUMO gaps, electron affinities, and photoelectron spectra have been computed and discussed. The simulated electron affinities and photoelectron spectra agree reasonably with experiments. With exceptionally low electron affinity and large HOMO-LUMO gap, In3P3 was identified as a magic-numbered cluster of relatively higher stability, in agreement with experimental observations.