• ab initio calculations;
  • cluster compounds;
  • extrapolation;
  • microsolvation;
  • vertical detachment energies


Structures and photoelectron spectral properties of InCO2 (n=1–7) clusters are presented at the level of second-order Møller–Plesset perturbation theory with relativistic corrections. Triple split-valence 6-311++G(d,p) basis set functions are employed herein. It is observed that the CO2 molecules approach the I anion from one side in all the clusters and that InCO2 clusters prefer the surface structure. The calculated vertical detachment energy of these clusters is in excellent agreement with the reported experimentally measured values (within 4 %). Efforts are also made to extract vertical detachment energy of large size of clusters, including the bulk. The extracted vertical detachment energy values for larger clusters (n=8–13) by employing the microscopic theory-based expression are also close (within 4 %) to that of the experimentally measured values.