The structure and electronic properties of CdS, CdSe, and CdTe thin films and multilayer CdS/CdSe/CdS and CdS/CdTe/CdS heterostructures simulating quantum wells of these compositions are performed using density functional theory and a slab approximation. Various crystal modifications and various crystallographic surfaces of the specified compounds are considered. In the calculations, the GGA approximation for the exchange-correlation functional (PW91) and ultrasoft pseudopotentials are used. For the systems in study, the work functions are calculated for various surfaces. The calculated structural data are in good agreement with experiments. The calculated surface reconstruction can be qualitatively described as an inward displacement of cadmium atoms into the surface crystal layer and an outward displacement of chalcogen atoms. The calculated surface energies indicate that the (110) surface formation energy is lower than the (100) surface formation energy. The calculated work functions decrease in the sequence CdS > CdSe > CdTe, while the calculated work functions for multilayer structures are between the corresponding values for the pure components of the structure.

The structure and properties of the (001) surface of indium oxide (In2O3) and indium tin oxide (ITO) are investigated theoretically. Ultrasoft pseudopotentials and the PBE exchange-correlation functional are used in our calculations. The calculated band structure of bulk In2O3, ITO, and their slabs with various surface oxidation levels are compared. Band structure features associated with surface states are detected. The dependence of the calculated electron work function for the In2O3 (001) and ITO (001) surfaces on the surface oxidation level is analyzed. It is found that the work function increases with the oxidation level of the surfaces.

Adsorption of simple organic and inorganic molecules on an amorphized silica gel surface is studied within the framework of density functional theory in the approximation of periodic crystalline slabs. Adsorption of water, ammonia, acetone, and ethanol molecules is examined. Most probable adsorption sites of molecules on the surface are calculated and the adsorption energies and bond lengths of molecules on the silica gel surface are estimated.

The effect of an alloying metal and its magnetic state on the hydrogen absorption energy has been investigated in the Pd-based alloys Pd3Me with 3d transition metals (Me = Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) using calculations from first principles. The full-potential and linearly augmented plane wave (FP LAPW) method has been used in the local density approximation (LDA) for the exchange-correlation potential in the framework of the density functional theory (DFT). It has been found that the hydrogen solubility in an alloy increases if the centers of mass of s and d metal bands and s hydrogen band shift strongly toward the Fermi level. The changes in properties of hydrogen absorption as a function of its position in a crystal lattice structure and magnetic state of an alloy have been analyzed.