A density-functional study of the structures and electronic properties of neutral, anionic, and endohedrally doped InxPx clusters

Abstract

We report extensive ab initio calculations of the structures, binding energies, and magnetic moments of In(x)P(x) and In(x)P(x) (-) clusters (x=1-15) using a density-functional method that employs linear combinations of pseudoatomic orbitals as basis sets, nonlocal norm-conserving pseudopotentials, and the generalized gradient approximation for exchange and correlation. Our results, which are compared with those obtained previously for some of these clusters by means of all-electron calculations, show that hollow cages with alternating In-P bonds are energetically preferred over other structures for both the neutral and anionic species within the range x=6-15. We also consider the endohedrally doped X@In(10)P(10) (X=Cr,Mn,Fe,Co) and Ti@In(x)P(x) (x=7-12) clusters. Our results show that, except for Ti@In(7)P(7) and Ti@In(8)P(8), the transition metal atoms preserve their atomic spin magnetic moments when encapsulated in the InP cages, instead of suffering either a spin crossover or a spin quenching due to hybridization effects. We also show that the stabilities of some empty and doped InP cages can be explained on the basis of the jellium model.