An ab initio Hartree-Fock approach aimed at directly obtaining the localized orthogonal orbitals (Wannier functions) of a crystalline insulator is described in detail. The method is used to perform all-electron calculations on the ground states of crystalline lithium fluoride and lithium chloride, without the use of any pseudo or model potentials. Quantities such as total energy, x-ray structur...

An ab initio method is developed for variational grand-canonical molecular electronic structure of open systems based on the Gibbs-Peierls-Boguliobov inequality. We describe the theory and a practical method for performing the calculations within standard quantum chemistry codes using Gaussian basis sets. The computational effort scales similarly to the ground-state Hartree-Fock method. The qua...

We discuss axially symmetric time-dependent Hartree-Fock calculations using a finite-range modification of the Skyrme energy functional. The finite-difference forms of the coordinate-space time-dependent Hartree-Fock equations, the method of time evolution, and other numerical aspects are presented. Detailed results for 84Krinduced deep-inelastic collisions with 208Pb at E 1,b = 494 MeV and wit...

We report lifetime measurements for three of the 5d96p levels in Au II and relativistic multiconfiguration Dirac–Fock (MCDF) calculations of lifetimes and transitions probabilities in this ion. The work was motivated by significant disagreements between previous experimental 5d96p lifetimes, obtained by means of the beam–foil (BF) method and theoretical data based on Hartree–Fock calculations i...

The Hartree-Fock approximation is of central importance to quantum chemistry. The assumption of electrons interacting with each other through a mean field sim;>lifiesthe electronic structure problem considerably, and provides the starting point for almost all approaches. However,it is curious to note that even this simplifying assumption was not sufficient to make electronic structue calculatio...

Methods: Following upon the work presented in Ref. [1], quadrupole-constrained Hartree-Fock calculations are used to create a potential energy surface. An isomeric state and a state beyond the second barrier peak are excited by means of instantaneous as well as temporally extended gauge boosts with quadrupole shapes. The subsequent deexcitation is studied in a time-dependent Hartree-Fock simula...

Relativistic Hartree–Fock and multiconfigurational Dirac–Fock calculations of atomic structure and transition rates have been carried out in trebly ionized lanthanum (La3+, Z = 57). The calculations have to cope with configuration interaction effects but also with the very complex situation of the collapse of the 4f wave function. The calculations are compared to experimental data obtained with...