相关论文: Model Calculations for Copper Clusters on Gold Ele…
In this work, we combine electron microscopy measurements of the surface compositions in Cu-Au nanoparticles and atomistic simulations to investigate the effect of gold segregation. While this mechanism has been extensively investigated…
Coupled-cluster theory with single, double, and perturbative triple excitations (CCSD(T)) -- often considered the "gold standard" of main-group quantum chemistry -- is inapplicable to three-dimensional metals due to an infrared divergence,…
A self-energy-functional approach is applied to construct cluster approximations for correlated lattice models. It turns out that the cluster-perturbation theory (Senechal et al, PRL 84, 522 (2000)) and the cellular dynamical mean-field…
The binding of clusters of metal nanoparticles is partly electrostatic. We address difficulties in calculating the electrostatic energy when high charging energies limit the total charge to a single quantum, entailing unequal potentials on…
The adsorption kinetics of CO on PdAu bimetallic clusters, containing 140 $\pm$ 12 atoms and a composition varying between 0% and 55% of Pd atoms, is investigated by a pulsed molecular beam method (MBRS). The clusters are grown on a…
Solute clusters affect the physical properties of alloys. Knowledge of the atomic structure of solute clusters is a prerequisite for material optimisation. In this study, solute clusters in a rapid-hardening Al-Cu-Mg alloy were…
We predict general trends for surface segregation in a binary metal cluster based on the difference between the atomic properties of the constituent elements. Considering the attractive and repulsive contributions of the cohesive energy of…
Metallic nanoclusters displaying electronic shell structure exhibit the special feature of a correlation between their geometry and the number of delocalized electrons . Their shape evolution can be described as a quantum oscillation…
A new method is introduced to study three-body clusters. Triangular configurations with ${\cal D}_{3h}$ point-group symmetry are analyzed. The spectrum, transition form factors and $B(E\lambda)$ values of $^{12}$C are investigated. It is…
Low-energy structures are found on the potential energy surfaces of the neutral, cationic, and anionic gold clusters Au_{5 \leq n \leq 8}^Z (Z = 0, \pm) and on the neutral potential energy surface of Au_9. These structures provide insights…
Coupled-cluster theories can be used to compute ab initio electronic correlation energies of real materials with systematically improvable accuracy. However, the widely-used coupled cluster singles and doubles plus perturbative triples…
We investigate the shifts of the core-level binding energies in small gold nanoclusters by using {\it ab initio} density functional theory calculations. The shift of the 4$f$ states is calculated for magic number nanoclusters in a wide…
We report the effects of variation in length on the electronic structure of CdSe nanorods derived from atomic clusters and passivated by fictitious hydrogen atoms. These nanorods are augmented by attaching gold clusters at both the ends to…
Icosahedral Au clusters with three and four shells of atoms are found to deviate significantly from the commonly assumed Mackay structures. By introducing additional atoms in the surface shell and creating a vacancy in the center of the…
The electronic structure of ultra-small Au clusters on thin MgO/Ag(001) films has been analyzed by scanning tunneling spectroscopy and density functional theory. The clusters exhibit two-dimensional (2D) quantum well states, whose shapes…
We perform coupled-cluster and diffusion Monte Carlo calculations of the energies of circular quantum dots up to 20 electrons. The coupled-cluster calculations include triples corrections and a renormalized Coulomb interaction defined for a…
We present ab-initio calculations of the magnetic moments and magnetic anisotropy energies of small FeCo clusters of varying composition on top of a Cu(100) substrate. Three different cluster layouts have been considered, namely 2x2, 3x3…
We present an implementation of equation of motion coupled-cluster singles and doubles (EOM-CCSD) theory using periodic boundary conditions and a plane wave basis set. Our implementation of EOM-CCSD theory is applied to study $F$-centers in…
An analysis of the structural properties of three-dimensional Coulomb clusters confined in a spherical parabolic trap is presented. Based on extensive high accuracy computer simulations the shell configurations and energies for particle…
An electrodynamical coupled cluster (CC) methodology starting from a covariant formalism and an equal time approximation, and finally based on the Dirac-Fock picture of the electron and positron fields and Coulomb gauge, is given here. The…