Nowadays the state of the art Density Functional Theory (DFT) codes are based on local (LDA) or semilocal (GGA) energy functionals. Recently the theory of a truly nonlocal energy functional has been developed. It has been used mostly as a post DFT calculation approach, i.e. by applying the functional on the charge density calculated using any standard DFT code, thus obtaining a new improved value for the total energy of the system. Nonlocal calculation is computationally quite expensive and scales as N^2 where N is the number of points in which charge density is defined, and a massively parallel calculation is essential for a wider applicability of the new approach. In this article we present a code which acomplishes this goal.

We develop a many-body description of ultrafast electron dynamics in surface bands appropriate for studying relaxation of hot electrons and holes excited in the processes of one- and two-photon photoemission and inverse photoemission from surfaces. The description is based on the formalism for calculation of quasiparticle survival probabilities combined with self-consistent treatment of the electronic response of the system. We show that the calculation of survival amplitudes which carry information on the quasiparticle decay and decoherence can be conveniently mapped onto the problem of renormalization of quasiparticles by the interactions with bosonized excitations constituting the system heatbath. Applying this approach to the benchmark Cu111 surface we are able to assess the regimes of preasymptotic non-Markovian quasiparticle dynamics in surface bands and locate transitions to the regime of exponential decay governed by the modified Fermi golden rule-type of transition rates. The general validity of these findings enables us to establish borderlines between different regimes of ultrafast electronic relaxation and on that basis to introduce a simple interpolation scheme for modeling of quasiparticle decay in the course of spectroscopic measurements.

We review theoretical treatments of physisorption of Xe on Cu(111) and Pt(111) surfaces within the recently proposed extended density functional approach that explicitly takes into account the van der Waals interactions among the constituents of adsorption systems. Based on tests of the various currently used approximations for the density functionals, and of the different treatments of long-range correlation effects which we carried out for a prototype system of a Kr dimer, we have adopted in the present study the schemes that are appropriate to systems consisting of nearly isolated fragments. In this approach the coefficients of van der Waals expansion are deduced from the DFT calculations of intrafragment electronic densities. Such generalized DFT calculations of potential energy surfaces yield a structure of Xe adlayers in good agreement with experiments and retrieve the dilation of the commensurate monolayer phase with strongly reduced intralayer Xe–Xe radial force constants. This approach provides a first principles interpretation of the observed vibrational properties of commensurate adlayers of Xe physisorbed on Cu(111) and Pt(111) surfaces.

We develop a many-body description of the nonadiabatic dynamics of quasiparticles in surface bands valid on an extremely ultrashort time scale by combining the formalism for the calculation of quasiparticle survival probabilities with the self-consistent treatment of the electronic response of the system. Applying this approach to the benchmark Cu(111) surface, we assess the behavior and intervals of preasymptotic electron and hole dynamics in surface bands and locate the transition to the asymptotic regime of the exponential quasiparticle decay characterized by the corrected Fermi golden rule-type of transition rate. The general validity of these findings enables distinguishing the various regimes of ultrafast electron dynamics that may be revealed in time resolved experiments.

We present a combined, experimental, and computational investigation of the growth mode and the valence-band structure of $\mathrm{Ag}∕\mathrm{Pd}(111)$, with the focus on the Ag $4d$ derived quantum well states. Low-energy electron diffraction and scanning-tunneling microscopy are used to determine epitaxial, layer-by-layer growth of silver on the palladium substrate. High-resolution (in both energy and angle) photoelectron spectra and ab initio density-functional band-structure calculations are compared for 1 and 2 ML silver films along the $\overline{\ensuremath{\Gamma}}\ensuremath{-}{\overline{M}}^{\ensuremath{'}}$ high symmetry line of the surface Brillouin zone. The observed $d$-derived electronic states and their dispersion are explained in terms of quantum well states. The interaction of the silver $4d$ electronic states with the palladium substrate is discussed.

We consider some recently developed schemes for treating van der Waals interactions within the density functional theory (DFT) on the widely discussed example of adsorption of Xe on Cu(111) and Pt(111) surfaces. Consistent with the overall weakness of the Xe surface and Xe-Xe interactions we assess the performance of the schemes that are appropriate to systems consisting of nearly isolated fragments in which the coefficients of the van der Waals expansion are deduced from DFT calculations. Such generalized DFT calculations of potential energy surfaces yield the structure of Xe adlayers in good agreement with experiments and retrieve the dilation of commensurate monolayer phase in which the intralayer Xe-Xe radial force constants are strongly reduced. This provides a first principles interpretation of the observed vibrational properties of adlayers, in general, and the much debated dispersion of in-plane polarized vibrations, in particular.

We present a combined, experimental, and computational investigation of the growth mode and the valence-band structure of Ag/Pd(111), with the focus on the Ag 4d derived quantum well states. Low-energy electron diffraction and scanning-tunneling microscopy are used to determine epitaxial, layer-by-layer growth of silver on the palladium substrate. High-resolution (in both energy and angle) photoelectron spectra and ab initio density-functional band-structure calculations are compared for 1 and 2 ML silver films along the Gamma-M-' high symmetry line of the surface Brillouin zone. The observed d-derived electronic states and their dispersion are explained in terms of quantum well states. The interaction of the silver 4d electronic states with the palladium substrate is discussed.

We present a new, efficient and robust method for solving electrostatic problems. The basic idea of the method is rather simple, but has not been exploited so far. The essence of the method is achieving of the equipotentiality of the conducting surfaces by iterative nonlocal charge transfer. Besides the simple physical idea, the computational behavior of the method is very appealing. It scales linearly in memory with the number of elements and it converges geometrically without the occurrence of Critical Slowing Down. The presented method can be extended in application to other types of problems, electrostatics being a very specific example in which one can remain only on the boundaries of the objects involved in the calculation. Due to high efficiency and low resource demands, this method could prove useful in many areas that require electrostatic calculations of high precision and detail—medical applications, charged particle detector/accelerator construction, printed electronics being just some of them.

We have studied the electronic states in 1-5 layers thick Ag films on V(100), by means of ab initio density functional calculations. Due to the mismatch of the electronic structure of Ag and V, quantum well states of both sp and d character localized on Ag films are formed. We find that the hybridization of the Ag quantum well states with the V orbitals is nevertheless important, and must be taken into account in order to fully understand the observed properties, in particular the energies and the dispersion of the photoemission peaks in ARPES experiments. We also discuss the character of the states on the first Ag layer with energies around the Fermi level which contribute dominantly to the tunneling current in STM experiments. We find that these states are largely localized on the Ag overlayers, which explains the appearance of standing waves around impurities which are observed in STM.

We have performed ab initio density functional calculations of thin Ag films on the Pd(111) surface. We have calculated the structural properties and the electronic bands of the Ag/Pd systems. There is a band gap in the electronic density of states around the centre of the two-dimensional Brillouin zone of the Pd(111) surface, which makes possible the formation of localised states in the adsorbed silver films. We find that quantum well states may form at binding energies around 4 eV.