Nurten Akman

Hydrogen storage capacity of titanium met-cars

The adsorption of hydrogen molecules on the titanium metallocarbohedryne (met-car) cluster has been investigated by using the first-principles plane wave method. We have found that, while a single Ti atom at the corner can bind up to three hydrogen molecules, a single Ti atom on the surface of the cluster can bind only one hydrogen molecule. Accordingly, a Ti8C12 met-car can bind up to 16 H2 molecules and hence can be considered as a high-capacity hydrogen storage medium. Strong interaction between two met-car clusters leading to the dimer formation can affect H2 storage capacity slightly. Increasing the storage capacity by directly inserting H2 into the met-car or by functionalizing it with an Na atom have been explored. It is found that the insertion of neither an H2 molecule nor an Na atom could further promote the H2 storage capacity of a Ti8C12 cluster. We have also tested the stability of the H2-adsorbed Ti8C12 met-car with ab initio molecular dynamics calculations which have been carried out at room temperature.

Confined states in multiple quantum well structures of SinGen nanowire superlattices

Mechanical properties, atomic and energy band structures of bare and hydrogen-passivated

The Wigner molecule in a 2D quantum dot

{\mathrm{Si}}_{n}{\mathrm{Ge}}_{n}

Interacting electrons in a 2D quantum dot

nanowire superlattices have been investigated by using first-principles pseudopotential plane-wave method. Undoped, tetrahedral Si and Ge nanowire segments join pseudomorphically and can form superlattice with atomically sharp interface. We found that

Half-metallic silicon nanowires: first-principles calculations.

{\mathrm{Si}}_{n}

Atomic and electronic structures of doped silicon nanowires: A first-principles study

nanowires are stiffer than

Ionization energies, Coulomb explosion, fragmentation, geometric, and electronic structures of multicharged boron clusters B(n) (n=2-13)

{\mathrm{Ge}}_{n}

Functionalization of silicon nanowires with transition metal atoms

nanowires. Hydrogen passivation makes these nanowires and

Fragmentation and Coulomb explosion of multicharged small boron clusters

{\mathrm{Si}}_{n}{\mathrm{Ge}}_{n}

Island shape, size and interface dependency on electronic and magnetic properties of graphene hexagonal-boron nitride (h-BN) in-plane hybrids

nanowire superlattice even more stiff. Upon heterostructure formation, superlattice electronic states form subbands in momentum space. Band lineups of Si and Ge zones result in multiple quantum wells, where specific states at the band edges and in band continua are confined. The electronic structure of the nanowire superlattice depends on the length and cross section geometry of constituent Si and Ge segments. Since bare Si and Ge nanowires are metallic and the band gaps of hydrogenated ones vary with the diameter,