Related papers: Triple differntial cross section for electron impa…
In quantum chemistry calculations, the correlation energy is defined as the difference between the Hartree-Fock limit energy and the exact solution of the nonrelativistic Schrodinger equation. With this definition, the electron correlation…
We study the single ionization of hydrogen and helium by the impact of a highly-charged Coulomb projectile. To interpretate the cross section we introduce a diagonal Pad\'{e} approximant. We find that the use of Pad\'{e}% [4,4] describes…
The expression of the electron broadening operator including the effect of penetrating collisions, i.e. for which the incoming electron enters the extent of bound-electron wavefunctions, is rather complicated, even for hydrogen. It involves…
The tunnel ionization of an electron bounded by two delta potentials under the influence of a constant electric field is considered. The equations for the electron current density for two different initial states are obtained. The…
We study electron loss from a hydrogen-like highly charged ion by the impact of equivelocity electrons and protons and also in collisions with hydrogen and helium. The collision velocity $v$ varies between $v_{min}$ and $v_{max}$, where…
The shape and absolute values of the generalized cross-sections of the two-photon resonant single ionization of the K-shell of ions of the isonuclear sequence of a heavy nickel atom (28Ni - Ni26+ - Ni24+ - Ni18+) have been theoretically…
A one parameter expression for the single ionization cross-section of atoms by electron impact is presented. Using this expression, the agreement obtained with available experimental data for 45 elements (from ionization threshold up to 200…
Rotational excitation of isotopologues of HCN and HNC by thermal electron-impact is studied using the molecular {\bf R}-matrix method combined with the adiabatic-nuclei-rotation (ANR) approximation. Rate coefficients are obtained for…
We present a nonperturbative numerical evaluation of the one-photon electron self energy for hydrogenlike ions with low nuclear charge numbers Z=1 to 5. Our calculation for the 1S state has a numerical uncertainty of 0.8 Hz for hydrogen and…
The hydrogen plasma is studied at temperatures T ~ 10^4 - 10^6 K using the free energy minimization method. A simple analytic free energy model is proposed which is accurate at densities up to 1 g/cc and yields convergent internal partition…
Schrodinger's equation predicts something very peculiar about the electron in the Hydrogen atom: its total energy must be equal to zero. Unfortunately, an analysis of a zero-energy wavefunction for the electron in the Hydrogen atom has not…
We explore excitation and ionization by neutron impact as a novel tool for the investigation of electron-electron correlations in helium. We present single and double ionization spectra calculated in accurate numerical ab-initio simulations…
We present a theoretical model for atomic hydrogen ionization by electron impact in the instantaneous approximation and the more accurate non-instantaneous approach using the methods of Quantum Electrodynamics, for the binary coplanar and…
Exact density functionals for the exchange and correlation energies are approximated in practical calculations for the ground-state electronic structure of a many-electron system. An important exact constraint for the construction of…
In our work we construct a Hamiltonian, whose eigenstates approximate the solutions of the self-consistent Hartree-Fock equations for nonrelativistic atoms and ions. Its eigenvalues are given by completely algebraic expressions and the…
In order to simulate the effects of energetic charged particles present in the solar wind colliding with the cometary gaseous formic acid molecule (HCOOH), laboratory experiments have been performed. The absolute ionisation and dissociation…
The momentum distribution of the electron in the reaction p+He $\rightarrow$ H + He$^{2+}$ + $e$ is measured for projectile energies $E_p$=300 and 630 keV/u at very small scattering angles of hydrogen. We mainly present two dimensional…
We study relativistic collisions between helium-like uranium ions initially in the ground state and atoms in which, in a single collision event, one of the electrons of the ion is emitted and the other is transferred into an excited state…
The compressibility of a two-dimensional electron system with spin in a spatially correlated random potential and a quantizing magnetic field is investigated. Electron-electron interaction is treated with the Hartree-Fock method. Numerical…
The solution of Dirac's equation for the hydrogen atom according to relativistic wave mechanics yields for each state a vectorial amplitude function with four components, two large and two small. Each such component has its characteristic…