Related papers: The planar-to-tubular structural transition in bor…
A new model that describes adsorption and clustering of particles on a surface is introduced. A {\it clustering} transition is found which separates between a phase of weakly correlated particle distributions and a phase of strongly…
Possible crystalline modifications of chemical compounds at low temperatures correspond to local minima of the energy landscape. Determining these minima via simulated annealing is one method for the prediction of crystal structures, where…
A progress report on two recent theoretical approaches proposed to understand the physics of irreversible fractal aggregates showing up a structural transition from a rather dense to a more multibranched growth is presented. In the first…
Using density-functional theory (DFT), we investigate the selectivity of adsorption of CO2 over N2 and CH4 on planar-type B clusters, based on our previous finding of strong chemisorption of CO2 on the B10-13 planar and quasiplanar…
Combining an electronic theory with molecular dynamics simulations we present results for the ultrafast structural changes in small clusters. We determine the time scale for the change from the linear to a triangular structure after the…
We have investigated the lowest-energy structures and electronic properties of the Au$_n$(n=2-20) clusters based on density functional theory (DFT) with local density approximation. The small Au$_n$ clusters adopt planar structures up to…
Low-energy structures of a hybrid system consisting of a polymer and an attractive nanowire substrate as well as the thermodynamics of the adsorption transition are studied by means of Monte Carlo computer simulations. Depending on…
Ultrathin planar absorbing layers, including semiconductor and metal films, and 2D materials, are promising building blocks for solar energy harvesting devices but poor light absorption has been a critical issue. Although interference in…
We use linear response theory in order to compute the light absorption spectrum, in the terahertz band, of a polariton system composed by excitons in a quantum dot very strongly coupled to the lowest photon mode of a thin micropillar. In a…
We used deep observations collected with ACS@HST to derive the fraction of binary systems in a sample of thirteen low-density Galactic globular clusters. By analysing the color distribution of Main Sequence stars we derived the minimum…
We have performed systematic large-scale all-electron correlated calculations on boron clusters B$_{n}$(n=2--5), to study their linear optical absorption spectra. Several possible isomers of each cluster were considered, and their…
Vibrational and electronic absorption spectra calculated at the (time-dependent) density functional theory level for the bismuth carbide clusters Bi$_{n}$C$_{2n}$$^+$ ($3 \le n \le 9$) indicate significant differences in types of bonding…
We present a spin-adapted time-dependent coupled cluster singles and doubles model for the molecular response to a sequence of ultrashort laser pulses. The implementation is used to calculate the electronic response to a valence-exciting…
Polaron formation plays a major role in determining the structural, electrical and chemical properties of ionic crystals. Using a combination of first principles calculations and scanning tunneling microscpoy/atomic force microscopy…
In this work, we employ density functional theory (DFT) to explore the structure of boron clusters doped with two aluminium atoms (B$_7$Al$_2$ or Al$_2$B$_7$). The results show that the most stable structure is a bipyramidal configuration…
The optical absorption spectrum of the three most stable isomers of the Ag11 system was calculated using the time-dependent density functional theory, with the generalized gradient approximation for the exchange and correlation potential,…
A combined approach of first-principles density-functional calculations and the systematic cluster-expansion scheme is presented. The dipole, quadrupole, and Coulomb matrix elements obtained from ab initio calculations are used as an input…
Monte Carlo computer simulations of a quasi two dimensional (2D) dipolar fluid at low and intermediate densities indicate that the structure of the fluid is well described by an ideal mixture of self-assembling clusters. A detailed analysis…
Absorption spectra of closed-shell Na_2, Na_3+, Na_4, Na_5+, Na_6, Na_7+, and Na_8 clusters are calculated using a recently implemented conserving linear response method. In the framework of a quasiparticle approach, we determine…
The absorption of large bipolarons is investigated using the path-integral method. The response of a bipolaron to an external electromagnetic field is derived in the framework of the memory-function approach. The bipolaron optical…