Burkhard Fricke

Universität Kassel

Quantum information-theoretical measure in terms of Shannon and Fisher entropy in conjugate position and momentum spaces provides important information about the localization/delocalization patterns of the inter-atomic charge density under arbitrary confining environments. In this article, we have attempted to employ such measures to the ground, ex...

The quantum information theoretic measures in terms of Shannon entropy and Fisher entropy (both in position and momentum spaces) on the ground, excited as well as virtual states arising out of the two-photon transitions (1s --> nl; n=2-4, l=0,2) of H atom embedded in classical weakly coupled plasma environment are done for the first time. Fourth or...

The effect of Debye and quantum plasma environment on the structural properties such as spin orbit splitting, relativistic mass correction and Darwin term for a few iso-electronic members of hydrogen viz. C5 +, O7 +, Ne9 +, Mg11 +, Si13 +, S15 +, Ar17 +, Ca19 + and Ti21 + has been analysed systematically for the first time for a range of coupling s...

Using time dependent coupled Hartree-Fock(TDCHF) theory, we estimate structural properties such as total energy, ionisation potential, static and dynamic polarizabilities, oscillator strengths and transition probabilities for the first three dipolar excitations 1s ²:¹Se → 1snp:¹Po (n = 2,3,4) and quadrupolar excitations 1s ²:¹Se → 1snd:¹De (n = 3,4...

Kα X-ray emission spectra of manganese compounds have been measured using an ultimate-resolution Bragg spectrometer optimised for long-term high-statistics measurements. Energies corresponding to the peak positions of the Kα lines were measured to a precision of 10–20 meV. Total line widths of the Kα1 and Kα2 components and their asymmetry have bee...

Hyperpolarizability of two electron atoms He, Li+, Be2+, B3+, and C4+ embedded under quantum plasma environment has been calculated for the first time using exponential cosine screened coulomb potential (ECSCP) arising out of the interaction of atomic charge cloud with such an environment. Coupled Hartree-Fock theory within variational scheme has b...

The lowest s → s line shifts of the alkali atoms Li and Na attached to 4He nanodroplets have been estimated using ab initio quantum chemical methods with a physically viable cluster model of alkali atom (Li/Na) on the surface of helium atoms. First, detailed non-relativistic calculations are made using size extensive Configuration Interaction (CIS(...

The electron screening correction in the X-ray transitions in muonic atoms is calculated within a relativistic SCF Hartree-Fock procedure for many transitions and all Z.

Effect of strongly coupled plasma on the excitation energies and transition probabilities for the respective transitions 1s2:1Se → 1sns:3Se (n = 2, 3, 4) and 1s2:1Se → 1snp:3Po (n = 2, 3, 4) allowed by magnetic dipolar and quadrupolar excitations have been analyzed for the first time for the two-electron ions C4+, O6+, Ne8+, Mg10+, Si12+, and S14+....

Systematic investigations on the hyperpolarizabilities of hydrogen and helium like ions up to nuclear charge Z = 7 under strongly coupled plasma environment have been performed. Variation perturbation theory has been adopted to evaluate such properties for the one and two electron systems. For the two electron systems coupled Hartree-Fock theory, w...

High-Z helium like ions represent the simplest multi electron systems for studying the interplay between electron–electron correlations, relativistic as well as quantum electrodynamical effects in strong fields. In contrast to the adjacent lithium like ions, however, almost no experimental information is available about the excited states in the hi...

The effect of strongly coupled plasma occurring in astrophysical context has been studied for the first time to estimate the energy levels of the autoionizing states of highly stripped astrophysically important ions Al11+, Si12+, P13+, S14+ and Cl15+ and also C4+ isoelectronic to helium. The transition energies corresponding to 1s 2:1Se → 2s 2:1Se,...

Laser induced fluorescence experiments indicate change of spectral line profiles of atoms and molecules compared to the free system when embedded under liquid helium. Based on relativistic density functional approach a model has been proposed here to estimate the width of the spectral lines embedded under liquid helium in which the central atom res...

The inner-shell couplings for Uq+-ions (73≤q≤91) moving moderately slow at ~69 MeV u−1 and bombarding thin Au targets have been investigated. Having established the definite survival probability of incoming projectile K vacancies in these targets in an earlier publication, the transfer of these vacancies to the target K-shell due to inner-shell cou...

Systematic analysis of the effect of Debye plasma on the hyperpolarizability of spherically confined hydrogen atom has been studied in detail for the first time to understand the behavior of non linear optical properties of atoms under such confinements. Variation perturbation theory is used for such studies. Hyperpolarizability values are enhanced...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Spectral line positions for the highly stripped helium like carbon, aluminium and argon embedded in intense plasma environments have been calculated theoretically to compare with the existing data available from laser plasma experiments. The changes in the ionization potentials for such ions have been determined and the excitation energies, oscilla...

Relativistic and electron correlation effects are investigated for the closed-shell superheavy-element monohydrides RgH, 112H+, 113H, 114H+, 117H, 118H+, 119H, and 120H+. Periodic trends are discussed by comparing the calculated properties to the ones for the lighter elements. The size of the relativistic effects varies considerably between the dif...

Quasi-molecular X rays observed in heavy ion collisions are interpreted within a relativistic calculation of correlation diagrams using the Dirac-Slater model. A semiquantitative description of noncharacteristic M X rays is given for the system Au-I.

Extern

Systematically enlarged multiconfiguration Dirac-Fock wave functions have been applied in order to investigate the forbidden lines among the 3s23p3 ground-state levels for phosphorus-like ions at the neutral end of the sequence. The probabilities and ratios of these lines are important in the diagnostics of astrophysical plasmas. In a recent comput...

This brief review is dedicated to provide possible interpretations of spectral properties such as the energy levels, spectral line positions and line profiles of atoms embedded in a liquid helium environment from a theoretical standpoint, keeping in view the wide range of availability of highly precise laser spectroscopic data in this field. Differ...

Accurate laser spectroscopic studies of the principal resonance transitions in Rb and Cs atoms embedded in liquid helium have shown appreciable line shifts and change in line profiles. A pilot attempt has been made here to compute ab-initio the spectral line shift of the resonance excitation lines in Rb under such a confinement. Relativistic densit...

Multiconfiguration Dirac-Fock method is employed to calculate the excitation energies, ionization potentials, oscillator strengths, and radii for all neutral and up to four times ionized species of element Uuq, as well as the homolog elements Ge, Sn, and Pb. Using an extrapolative scheme, improved ionization potentials of Uuq were obtained with an...

The onset of antiprotonic X-ray transitions at high principal quantum numbers and the occurence of electronic X-rays in antiprotonic argon, krypton, and xenon has been analyzed with the help of Multiconfiguration Dirac-Fock calculations. The shell-by-shell ionisation by Auger electron emission, characterised by appearance and disappearance of X-ray...

The progress of differential studies of ion-atom/molecule collisions using the reaction microscope was reported. The state-selective and angular differential cross sections were measured for slow ion-atom collisions. In this paper we focus on the two-electron processes, namely double electron capture and transfer ionization, occurring in the collis...

Fully relativistic (four-component) density-functional theory calculations were performed for intermetallic dimers MM', where M=Ge, Sn, Pb, and element 114, and MM'=group 10 elements (Ni, Pd, and Pt) and group 11 elements (Cu, Ag, and Au). PbM and 114M, where M are group 14 elements, were also considered. The results have shown that trends in spect...

Highly differential experimental results of the scattering system He++ on He at 30 keV are presented as well as a complete unified theoretical description where excitation, transfer and ionization are treated simultaneously on an ab initio level. The agreement even for highly differential cross sections is nearly complete although no explicit corre...

Multi-configuration Dirac-Fock method (MCDF) is employed to calculate excitation energies, ionization potentials and oscillator strengths for all neutral and up to 5 times ionized species of element Uub, as well as the homologue elements Zn, Cd and Hg. On the basis of not too extended MCDF calculations, we studied some peculiar properties of elemen...

Excitation line shifts of the principal resonance transitions in alkali atoms sodium and cesium embedded inside the liquid helium environment have been calculated using four-component relativistic density functional theory. The effect of the liquid helium environment is assumed to be represented by a cluster of 14 atoms surrounding the central alka...

Fully relativistic four-component density functional theory with the general gradient approximation calculations have been performed to determine the adsorption energy and position of the superheavy element 112 on a Au surface. Extended cluster as well as embedded cluster calculations were used to simulate the surface which allow for the top, bridg...

Adsorption of element 112 on various types of surfaces was studied on the basis of fully relativistic four-component Density-Functional Theory (DFT) electronic structure calculations for atoms, dimers and atom-cluster systems. Using models of localized and mobile adsorption, the equilibrium adsorption temperature for element 112 is predicted with r...

The interatomic potential of the ion-atom scattering system IN+-I at small intermediate internuclear distances is calculated for different charge states N from atomic Dirac-Focker-Slater (DFS) electron densities within a statistical model. The behaviour of the potential structures, due to ionized electronic shells, is studied by calculations of cla...

A review of relativistic atomic structure calculations is given with a emphasis on the Multiconfigurational-Dirac–Fock method. Its problems and deficiencies are discussed together with the contributions which go beyond the Dirac–Fock procedure.

The concept of a "Superheavy Quasiatom" is discussed. Radiative transition times are compared with the lifetime of the intermediate system, cross sections are calculated within a two-collision model and induced transitions and their anisotropic emission are discussed. Recent experimental and theoretical results are presented from collision systems...

Relativistic Auger rates for the 2p spectra of Mg-like ions have been calculated in the atomic range 13 ≤ Z ≤ 36. We used the multiconfiguration Dirac-Fock method but beyond a simple frozen-orbital approach we include also relaxation for the bound electrons and the interchannel interaction between the continuum states. Both effects may alter the in...

A super heavy element Uub (Z = 112) has been studied theoretically in conjunction with relativistic effects and the effects of electron correlations. The atomic structure and the oscillator strengths of low-lying levels have been calculated, and the ground states have also been determined for the singly and doubly charged ions. The influence of rel...

The effect of plasma environment on the binding energy of the Coulomb three body molecular ion has been analyzed within nonrelativistic framework. Variational method has been adopted using multi-exponent correlated basis sets involving inter particle coordinates. The effect of external plasma has been incorporated using Debye screening model of the...

Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-...

Recent high precision measurements on the lifetime of the metastable 6s[3/2]2 state of atomic xenon display a difference with previous predictions by a factor of 2–3. In the present work, a system-atic relaxation and correlation approach, which has been developed on the basis of a widely used multi-configuration Dirac-Fock method, is applied to stu...

A fully relativistic four-component Dirac-Fock-Slater program for diatomics, with numerically given AO's as basis functions is presented. We discuss the problem of the errors due to the finite basis-set, and due to the influence of the negative energy solutions of the Dirac Hamiltonian. The negative continuum contributions are found to be very smal...

Relativistic multi-configuration Dirac Fock (MCDF) wavefunctions coupled to good angular momentum J have been calculated for low lying states of Ba I and Ba II. These wavefunctions are compared with semiempirical ones derived from experimental atomic energy levels. It is found that significantly better agreement is obtained when close configuration...

The investigation of quasimolecular x-rays from superheavy collision systems with bare or H-like projectiles seems to be a promising approach to get information about the behaviour of inner shell electrons with energy eigenvalues in the vicinity of the negative continuum. We present calculations of the MO x-ray spectra for the system U92+-Pb for va...

Multiconfiguration Dirac–Fock (MCDF) wave functions have been applied for many years to study excitation energies, transition probabilities, and lifetimes along various isoelectronic sequences. More recently, large-scale computations became feasible also for open-shell atoms and have been carried out for selected, multiple charged ions of the iron...

In order to describe an ion-atom collision in a fully quantum-mechanical way we solve full relativistically the time-dependent Dirac equation. In this coupled-channel formulation which includes not only internuclear distance-dependent optimized atomic basis functions, but also continuum functions we describe electron transfer, excitation and ioniza...

The finite element method (FEM) is now developed to solve two-dimensional Hartree-Fock (HF) equations for atoms and diatomic molecules. The method and its implementation is described and results are presented for the atoms Be, Ne and Ar as well as the diatomic molecules LiH, BH, N2 and CO as examples. Total energies and eigenvalues calculated with...

Following an earlier observation in F VI we identified the line pair 1s2s2p2 5P-1s2s2p3d 5Po, 5Do for the elements N, O, Mg, and tentatively for Al and Si in beam-foil spectra. Assignment was established by comparison with Multi-Configuration Dirac-Fock calculations along the isoelectronic sequence. Using this method we also identified some quartet...

In continuation of our previous work on the quintet transitions 1s2s2p2 5P-1s2s2p3d 5Po, 5Do, results on other n = 2 - n' = 3 quintet transitions for elements N, O and F are presented. Assignments have been established by comparison with Multi-Configuration Dirac-Fock calculations. High spectral resolution on beam-foil spectroscopy was essential fo...

In continuation of our previous work on doubly-excited ions with three and four electrons we present the first results on optical transitions in the term system of doubly-excited ions with five electrons. Transitions between such sextet states were identified in beam-foil spectra of the ions nitrogen, oxygen and fluorine. Assignments were first est...

A multi-configuration Dirac-Fock study of magnetic dipole transitions in beryllium and boron-like argon was reported. An atomic state wavefunction was approximated by a linear combination of configuration state functions (CSF). The rearrangement of the electron density due to transition was incorporated by applying an independent optimization proce...

On the basis of a multiconfiguration Dirac–Fock method, a systematic study has been carried out for the decay process of the 1s2s 2 2 S 1/2 state of Li-like ions. It is found that the decay properties of these states are quite different along the isoelectronic sequence: for low-Z ions up to Z = 30, the Auger decay channel is dominant; for medium-Z...

Large-scale multiconfiguration Dirac-Fock wavefunctions have been used to study excitation energies and lifetimes of the 3s2 3p4 3d configuration in the chlorine isoelectronic sequence. We present an ab-initio calculation of all dipole allowed transitions from 3s2 3p4 3d to the 3s2 3p5 (J = 1/2, 3/2) ground state levels for 6 ions in the atomic ran...

Without Abstract

We report on results of four-component moment-polarized relativistic density functional calculations for open shell systems. Especially, in this contribution we focus on atoms with open shells. The results obtained so far show, that atomic ground state energies can be calculated with good accuracy. Thus, more accurate binding energies for molecules...

The non-collinear and collinear descriptions within relativistic density functional theory is described. We present results of both non-collinear and collinear calculations for atoms, diatomic molecules, and some larger molecules. We find that the accuracy of our density functional calculations for the smaller systems is comparable to good quantum...

The influence of relativistic effects on properties and volatility of the group-8 tetroxides MO4, where M=Ru, Os, and element 108, Hs, was studied on the basis of results of the fully relativistic (four component) and nonrelativistic density functional theory calculations. Relativistic effects were shown to increase bond strengths and decrease bond...

Predictions of chemical behaviour of element 112 with respect to that of Hg for gas-phase chromatography experiments have been made on the basis of fully relativistic four-component Density-Functional Theory (DFT) electronic structure calculations for intermetallic compounds of Hg and element 112. Using a model of localized adsorption, the equilibr...

Using a sophisticated full relativistic all-electron density functional method we are able to describe the correct magnetic ground states of three organic molecules which are chosen as first examples to proof the quality of the method. S=0 for 3,4-dimethyl-tetrahydrofuran and 3,4-dimethyl-tetrahydrothiophene biradicals and S=1 for 1,1,3,4-tetrameth...

The study of the collinear and noncollinear description for the electric and magnetic properties of molecules, based on the use of relativistic density functional theory (DFT), was presented. The analysis study performed a spin-polarized collinear and a spin-polarized noncollinear calculation. The change in the bond energy of the molecular system a...

We use the newly developed non-collinear spin polarized density functional method to describe the tetrachlorides of element rutherfordium (Rf) and its homologues. It is the first time that a real three-dimensional molecule is described with this method. Without any additional corrections (used so far for the atomic values) we get nearly complete ag...

The theoretical description of the adsorption of atoms on surfaces is still a big problem especially when the atoms involved are very heavy such that relativistic effects play an important role. During the last years we have developed a relativistic molecular program [#!prog!#] which solves the relativistic Kohn-Sham equations with the use of vario...

Within full relativistic four-component ab initio density functional calculations we examined the adsorption of a Cu adatom on a Cu(100)-surface. The surface was simulated by a cluster of Cu atoms in which the number of atoms was successively increased to 99 atoms. Through extensive studies we were able to get convergence in adsorption energy and b...

Within full relativistic four-component ab initio density functional calculations, we examined the adsorption of a Cu-adatom on a Cu(100)-surface. As a first step we simulated the surface by a cluster of atoms and increased the size successively up to nearly 100 atoms. We found that using more than 60 atoms causes no significant changes in adsorpti...

The 17 levels of the 3 d 10 , 3 d 9 4 s and 3 d 9 4 p configurations, and the electric-dipole transitions among these levels are calculated for the three nickel-like ions Se6+, Y11+ and Sn22+ by using large-scale multiconfiguration Dirac-Fock wavefunctions. From these computations, the excitation energies and transition probabilities as well a...

The 17 levels of the 3d(10), 3d(9)4s and 3d(9)4p configurations, and the electric-dipole transitions among these levels are calculated for the three nickel-like ions Se6+, Y11+ and Sn22+ by using large-scale multiconfiguration Dirac-Fock wavefunctions. From these computations, the excitation energies and transition probabilities as well as the life...

We have investigated non-thermal desorption of metal atoms using laser light in a wide wavelength range, i.e. from 355 to 1064 nm. Rough Na and K films served as model systems for bond breaking of Na and K atoms. The results demonstrate that localized electronic excitations on metal surfaces can be exploited to desorb atoms from a well-defined bind...

Within full relativistic four-component ab initio density-functional calculations we studied the desorption of metal atoms induced by laser light. Recent experiments with K and Na nanoparticles showed a nonthermal resonant dependence of the desorption rate with respect to the applied photon energy without being accompanied by surface plasmon excita...

First full-relativistic density functional calculations with the extension of the spin-polarization functional for the relativistic density functional theory in their collinear and noncollinear form are presented here for the molecular system Pt2. The agreement with experiment is very good.

Fully relativistic (four-component) density-functional calculations were performed for the element 112 dimers (112)X (X = Pd, Cu, Ag and Au) and those of its lighter homolog, Hg. A relatively small decrease of about 15–20 kJ/mol in bonding was found from the HgX to (112)X compounds. Respectively, the bond lengths were increased by 0.06 Å on the ave...

During recent years, the RACAH program has been found to be a fast and reliable alternative for simplifying typical expressions from the theory of angular momenta. Here, we review the recent developments for this package and illustrate how it can be applied to the study of many-particle systems.

The structure of the heavy elements has attracted much inter- est since the earlier days of quantum mechanics. It was soon re- alized that the chemical behavior is a result of the structure of the outer valence electrons of the atoms. The discovery and avail- ability of the actinides and transactinides in physical and chem- ical research started th...

Within full relativistic four-component ab initio density functional cluster calculations we are now able to present results for the adsorption energy and bond distance of single atoms on surfaces. In order to compare with other (non-relativistic) calculations we have chosen Cu on a Cu(100) surface as an example. The convergence with respect to the...

Large multiconfiguration Dirac–Fock calculations were performed for all neutral and up to 7 and 8 times ionized species of elements 107 and 108, respectively, as well as all the homologous elements Mn, Tc, Re, Fe, Ru, and Os for a number of different total angular momenta. Comparison of the resulting ionization potentials to the known values of the...

Spherical harmonics play a crucial role in theoretical physics since they represent a complete and orthonormal set of functions on the unit sphere. The spherical harmonics are therefore applied in many different fields of physics including classical field theory as well as the treatment of quantum many-particle systems. Along with their well-known...

: We present recent theoretical results for the V3 and Au4 clusters. Calculations of the V3 doublet system indicate that the 6-311+G(d) basis set is sufficiently flexible to provide reliable minimum energy structures and vibrational frequencies, that these structures and frequencies are insensitive to spin contamination of the wave function when th...

Fully relativistic density functional calculations have been performed for group 8 tetroxides MO4, where M=Ru, Os, and element 108, Hs. The electronic structure analysis has shown HsO4 to be very similar to OsO4, with the covalence and stability increasing from OsO4 to HsO4. Using models of atom-slab interactions, adsorption enthalpies of RuO4 and...

A cluster embedding scheme for the investigation of the adsorption of adatoms on metal surfaces within the relativistic density functional theory is presented. Comparing the results of the adsorption of a single Al atom on an Al(1 0 0) surface good agreement with other descriptions using different methods is observed. This indicates, that the embed...

We report on results of a theoretical study of the adsorption process of a single carbon oxide molecule on a platinum (111) surface. A four-component relativistic density-functional method was applied to account for a proper description of the strong relativistic effects. A limited number of atoms in the framework of a cluster approach is used to d...

We report on results of a theoretical study of the adsorption process of a single carbon oxide molecule on a Platinum (111) surface. A four-component relativistic density functional method was applied to account for a proper description of the strong relativistic effects. A limited number of atoms in the framework of a cluster approach is used to d...

An extension to the RACAH program is presented for calculating standard quantities in the decomposition of many-electron matrix elements in atomic structure theory. These quantities include the coefficients of fractional parentage, the reduced coefficients of fractional parentage as well as reduced and completely reduced matrix elements for several...

The low-lying level structure and the 3d94p−3d10 resonance and intercombination transitions of the spectrum CuII have been studied by using large-scale multiconfiguration Dirac–Fock wavefunctions. Excitation energies and transition probabilities are calculated by including all dominant effects of relativity, correlation, and of the rearrangement of...

We report on the implementation and application of analytical energy gradients in four-component relativistic density-functional theory. Comparisons with numerical gradients for heavy diatomic molecules show good agreement. Results of geometry optimizations within the relativistic local-density approximation on heavy-element compounds are presented...

The quasimolecular M radiation emitted in collisions between Xe ions of up to 6 MeV energy and solid targets of Ta, Au, Pb and Bi, as well as a gaseous target of Pb(CH3)4, has been studied. Using a realistic theoretical correlation diagram, a semiquantitative explanation of the observed peak structure is given.

In the collision system Xe-Ag, the thresholds for excitation of quasimolecular L radiation and characteristic Ag L radiation have been found to lie at about 5 MeV and 1 MeV, respectively. These results are discussed on the basis of ab initio calculations of the screened interaction potential and the electron-correlation diagram.

A comparison between experimental and calculated spectral shape and energy dependence of the M MO X-ray anisotropy in heavy-ion collisions of I on Au is presented. The calculation is performed within the kinematic-dipole model of anisotropy using MO X-rays determined from SCF relativistic correlation diagrams.

In order to describe processes which are localized on a surface or inside the bulk of a solid, molecular calculations of an inner cluster may be adequate as long as the effect of the outer environment is taken into account via an embedding-method. Using a relativistic density functional method for the self-consistent cluster calculation we have dev...

We present molecular-orbital x-ray spectra from collision systems with highly charged projectiles calculated with a time-dependent coupled channel method using relativistic molecular Dirac-Fock-Slater wave functions and full radial and rotational couplings. The spectra of the system Cl16+-Ar are investigated with respect to the dynamics and the num...

Structural stability and energetics of gold microclusters Aun (n=313,19-555) have been investigated by molecular-dynamics simulations. A model potential energy function has been parametrized for the gold element by using the dimer interaction potential energy profile of the Au2, which is calculated by relativistic density functional method. Stable...

Using a self-consistent relativistic molecular density-functional method we have calculated adsorption energies and bond lengths of adatoms on surfaces simulated by clusters within the full relativistic description. The results indicate that our method is working so well that first big clusters can be handled in a realistic time and second the nume...

Diffusion of compact hexagonal Ir7 on Ir(1 1 1) is examined to identify mechanisms by which diffusion takes place and to find an explanation for the unusually high prefactors measured experimentally. From molecular dynamics, the analysis of displacement patterns, and total energy calculations, various non-equivalent processes are found which preser...

We reply to the comment on our paper “Four-component relativistic density functional calculations of heavy diatomic molecules” [J. Chem. Phys. 112, 3499 (2000)] in which the values of our calculated spectroscopic constants for heavy diatomic molecules were reinvestigated. We point out that the improved spectroscopic constants presented by Liu and v...

The physical origin of tip-induced motion of Cu adatoms on anisotropic Cu surfaces is investigated by means of total energy calculations which are based on three different semi-empirical potentials. The calculations show that for certain tip–adatom distances the activation barrier for the adatom to move towards the tip disappears completely, wherea...

Calculations of total and binding energies of group IV tetrachlorides MCl4 (M = Ti, Zr, Hf, and element 104, Rf) were performed using the four-component fully relativistic density functional method. The calculations show the binding energies to be in good agreement with thermochemical dissociation energies obtained via the Born−Haber cycle. The met...