Ab initio study of silver bromide AgnBrp(+) clusters (n <= 6, p=n, n-1)

Ab initio calculations in the framework of the density functional theory (D FT) with 19-electron pseudopotential on silver atoms are performed to study the lowest-energy isomers of silver bromide clusters AgnBrp(+) (n less tha n or equal to 6, p = n, n - 1). The stability, the structural and electroni c properties of neutral, and positively charged systems are examined. The B 3LYP functional has been used. For the smallest species, the DFT/B3LYP resu lts are very close to those obtained with multireference configuration inte raction or coupled cluster methods. In AgnBrn - 1 clusters, the excess elec tron density shows a picture intermediate between that observed in alkali h alide clusters (F-center or localization on a pending alkali atom) and that suggesting partial delocalization on a dimer or trimer silver subunit, Iso mer stabilities, fragmentation energies, electric dipole moments, adiabatic and vertical ionization potentials are calculated. The use of 11-electron pseudopotential on silver is discussed. (C) 2001 American Institute of Phys ics.