相关论文: Structural properties and optical response of Na c…
We investigate the dynamics of Na clusters embedded in Ar matrices. We use a hierarchical approach, accounting microscopically for the cluster's degrees of freedom and more coarsely for the matrix. The dynamical polarizability of the Ar…
We present a microscopic model for Na clusters embedded in raregas matrices. The valence electrons of the Na cluster are described by time-dependent density-functional theory at the level of the local-density approximation (LDA). Particular…
Using a combined quantum mechanical/classical method, we study the collisions of small Na clusters on large Ar clusters as a model for cluster deposit. We work out basic mechanisms by systematic variation of collision energy, system sizes,…
e analyze the excitation of Ar substrate in contact with Na clusters using a previously developed hierarchical model for the description of the system constituted of a highly reactive metal cluster in contact with a rather inert substrate.…
The microscopic structure of two amorphous materials with extreme nonlinear optical properties has been studied. One of these materials exhibits second harmonic generation, while another material of similar molecular structure emits…
The low-energy structures of mixed Ar--Xe and Kr--Xe Lennard-Jones clusters are investigated using a newly developed parallel Monte Carlo minimization algorithm with specific exchange moves between particles or trajectories. Tests on the…
Results of a theoretical study of the electronic properties of (Si)Ge and (Ge)Si core/shell nanoparticles, homogeneous SiGe clusters, and Ge$|$Si clusters with an interphase separating the Si and Ge atoms are presented. In general, (Si)Ge…
Using a combined quantum mechanical/classical method, we study the dynamics of deposition of small Na clusters on Ar(001) surface. We work out basic mechanisms by systematic variation of substrate activity, impact energy, cluster…
We investigate the dynamics of deposition of small Na clusters on MgO(001) surface. A hierarchical modeling is used combining Quantum Mechanical with Molecular Mechanical (QM/MM) description. Full time-dependent density-functional theory is…
Composition, atomic structure, and electronic properties of TM$_x$Mg$_y$O$_z$ clusters (TM = Cr, Ni, Fe, Co, $x+y \leq 3$) at realistic temperature $T$ and partial oxygen pressure $p_{\textrm{O}_2}$ conditions are explored using the {\em ab…
We present recent theoretical investigations on the dynamics of metal clusters in contact with an environment, deposited of embedded. This concerns soft deposition as well as irradiation of the deposited/embedded clusters by intense laser…
The magnetic structures of small clusters of Fe, Mn, and Cr supported on a Cu(111) surface have been studied with non-collinear first principles theory. Different geometries such as triangles, pyramids and wires are considered and the…
The optical properties of nanoparticle clusters vary with the spatial arrangement of the constituent particles, but also the overall orientation of the cluster with respect to the incident light. This is particularly important in the…
We develop a microscopic model for the interaction of small rare gas clusters with soft X-ray radiation. It is shown that, while the overall charging of the clusters is rather low, unexpectedly high atomic charge states can arise due to…
The structure of nanoclusters is complex to describe due to their noncrystallinity, even though bonding and packing constraints limit the local atomic arrangements to only a few types. A computational scheme is presented to extract…
The addition of small impurities, such as a single proton charge carrier, in noble gas clusters has recently been shown to have considerable effects on their geometries and stabilities. Here we report on a mass spectrometric study of…
In situ morphological investigation of the {105} faceted Ge islands on the Si(001) surface (hut clusters) have been carried out using an ultra high vacuum instrument integrating a high resolution scanning tunnelling microscope and a…
Size and composition of clusters produced by adiabatic expansion of binary gas mixtures (Ar-Kr, Kr-Xe, and N2-Ar) with various component concentrations are studied by using electron-diffraction technique. The resulting homogeneous and…
We consider the interaction of electromagnetic radiation of arbitrary polarization with multi-level atoms in a self-consistent manner, taking into account both spatial and temporal dependencies of local fields. This is done by numerically…
Chiroptical responses in atomic systems are usually weak, as they arise from the interference between electric- and much weaker magnetic-dipole transitions. We show that atoms arranged in chiral geometries can instead exhibit a strong…