Density functional theory calculations have been carried out to study the process of NO adsorption on neutral, anionic and cationic Ag8 clusters. Three cluster types have been considered in our study: D2d and Td structures are the most stable isomers in gas phase and C1 structure, which has the geometry of the most stable isomer adsorbed on rutile TiO2 (1 1 0) surface. Adsorption energies, N-O bond lengths and corresponding N-O vibration frequencies have been calculated for all structures. It has been shown that in the case of NO interaction with D2d structure the corresponding adsorption energies grow in the following order: Eads(cation) < Eads(neutral) < Eads(anion). The same regularity has been observed for NO interaction with silver tetramers in our previous study. For the Td structure the highest adsorption energy is also observed in case of anionic complex. However, for C1 structure other dependence has been observed: Eads(anion) < Eads(cation) < Eads(neutral). The adsorption of NO on neutral Ag8 cluster (C1 structure) is characterized by the largest N-O bond elongation which should be useful for NO fragmentation process.

Gold clusters synthesized by the solution-based growth technique have exhibited ultraviolet (UV) light emission with nearly zero Stokes shift. Atomic arrangement decided optical properties of the Au microclusters have been studied extensively. In addition to the time-of-flight mass spectra, the comparison of experimental and theoretical emission and absorption spectra confirms the presence of Au8 clusters with the planar hexagon+1 -shaped geometry. The observed UV emission is attributed to the transition from the highest occupied to the lowest unoccupied molecular orbitals of the hexagon +1 structured Au8 clusters.

Characteristics of photoelectron spectrum of Au2- and Au 4- clusters were calculated using different functionals and basis sets, and the results were compared with experimental data. The TD-B3LYP/LANL2Z method was shown to provide for calculation of these characteristics with good accuracy. Based on these results we suggested the methods and carried out appropriate calculations of the absorption and emission for different isomers of Au8 clusters. It was shown that the best agreement with the experimental data is observed for the planar C2ν "hexagon+1" structure, therefore, this is the structure observed experimentally. The calculated value of the Stokes shift for the specified structure does not exceed 12 nm, which is also in good agreement with experimental results.

Based on both total energy calculations and comparison of experimental and calculated characteristics of photoelectron spectra (PHES), the structural assignment of Cu11-, Cu12- and Cu13- clusters has been made using DFT model with previously developed S2LYP functional. In case of Cu13- cluster our decisions were also based on similarity of the geometries of copper and sodium clusters. The calculated characteristics of PHES for all the assigned structures are in excellent agreement with the experimental ones. The assigned geometries of Cu11- and Cu12- have been compared with those of recently established structures of silver clusters, which turned out to be very similar. In the meantime, the structure of the most stable Cu13- cluster is significantly distorted in comparison with the structure of Na13- cluster.