EJectron density distriiutions, derived from ap initio molecular wavefunttions, have been calculated for CNand SCNions. From these dynamic densities were calculated assuming-rigid body thermal. vibrations of the molecules. Comparison with the difference density in NaCN + 2&O, NaSCN and N&SCW, observed by X-ray diffraction, is fair. Remaining differences between theory and experiment are discuss...

Ground-state deformations, binding energies, and potential energy surfaces have been calculated for eveneven dysprosium isotopes between 160Dy and 180Dy in the framework of density-dependent Hartree-Fock calculations with BCS pairing correlations. Further deformed Hartree-Fock with angular-momentum projection and band-mixing calculations explore the yrast spectra of the nuclides approaching the...

Closed-form expressions for the first three terms in the perturbation expansion of the exact energy and Hartree-Fock energy of the lowest singlet and triplet states of the Hooke's law atom are found. These yield elementary formulas for the exact correlation energies (-49.7028 and -5.807 65 mE(h)) of the two states in the high-density limit and lead to a pair of necessary conditions on the exact...

The accuracy of two widely used scalar relativistic Hartree-Fock pseudopotentials, the Trail-Needs-Dirac-Fock (TNDF) and the Burkatzki-Filippi-Dolg (BFD) pseudopotentials, is assessed. The performance of the pseudopotentials is tested for a chemically representative set of 34 first-row molecules. All comparisons are made at the Hartree-Fock level of theory, and both sets of pseudopotentials giv...

Two different approximation schemes for the self-consistent solution of the relativistic Brueckner-Hartree-Fock equation for finite nuclei are discussed using realistic One-Boson-Exchange potentials. In a first scheme, the effects of correlations are deduced from a study of nuclear matter and parameterized in terms of an effective σ, ω and π exchange. Employing this effective interaction rela-t...

An ab initio Wannier-function-based approach to electronic groundstate calculations for crystalline solids is outlined. In the framework of the linear combination of atomic orbitals method the infinite character of the solid is rigorously taken into account. The Hartree-Fock groundstate energy, cohesive energy, lattice constant and bulk modulus are calculated in a fully ab initio manner as it i...

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...

We study the renormalization problem for the Hartree–Fock approximation of the O(N)−invariant φ model in the symmetric phase and show how to systematically improve the corresponding diagrammatic resummation to achieve the correct renormalization properties of the effective field equations, including Renormalization–Group invariance with the one–loop beta function. These new Hartree–Fock dynamic...

Using the recently introduced maximum overlap method and Hartree–Fock Perturbation Theory (HFPT), we compute Hartree–Fock (HF) wavefunctions for triplet 1s ns states of the helium atom. Comparison with near-exact results from Nakatsuji’s free ICI method reveals that HF theory provides a simple route to accurate energies of these Rydberg states, especially for large n. © 2009 Wiley Periodicals, ...

We describe the implementation of analytical Hartree-Fock gradients for periodic systems in the code CRYSTAL, emphasizing the technical aspects of this task. The code is now capable of calculating analytical derivatives with respect to nuclear coordinates for systems periodic in 0, 1, 2 and 3 dimensions (i.e. molecules, polymers, slabs and solids). Both closed-shell restricted and unrestricted ...