The solution of the Hartree-Fock equations involves the iterative construction of the Fock matrix based on approximate molecular orbit& and the diagonal&&ion of that Fock matrix to obtain new approximations to those orbitals. A significant portion of this work is unnecessary, however, because the occupied molecular orbitals, which are required to construct the Fock matrix, represent a small fra...

In this paper we begin the development of a formalism for the description of high energy neutrino interactions. It is based upon field theory quantized on a null plane. We set up the general formalism as well as some techniques needed to perform phenomenological calculations. We show that the formalism developed by Wolfenstein is recovered at the cost of making two approximations: one has to tr...

We present a relation which connects the propagator in the radial (Fock-Schwinger) gauge with a gauge invariant Wilson loop. It is closely related to the well-known field strength formula and can be used to calculate the radial gauge propagator. The result is shown to diverge in four-dimensional space even for free fields, its singular nature is however naturally explained using the renormaliza...

A relativistic extension of the particle-particle hole-hole ring-diagram many-body formalism is developed by using the Dirac equation for single-particle motion in the medium. Applying this new formalism, calculations are performed for nuclear matter. The results show that the saturation density is improved and the equation of state becomes softer as compared to corresponding Dirac-Brueckner-Ha...

We present ab initio Hartree-Fock lattice calculations on a series of heterocyclic and other compounds. Some of these have previously been studied by cluster calculations with the same D Z basis sets at the SCF level. The electric field gradients at the nitrogen centres, are related to NQR experimental determinations of nuclear quadrupole coupling constants. The compounds studied include imidaz...

The copper Kα photoemission spectra is one of the most widely studied. Recent Dirac-Fock calculations have produced transition energies in good agreement with experiment, though they have relied on approximations that may not be transferable to other complex atoms in which uncertainties in theoretical results are dominated by poor convergence. Through a detailed examination of convergence issue...

Full three dimensional static and dynamic mean field calculations using collocation basis splines with a Skyrme type Hamiltonian are described. This program is developed to address the difficult theoretical challenges offered by exotic nuclei. Ground state and deformation properties are calculated using static HartreeFock, Hartree-Fock+BCS and constrained Hartree-Fock models. Collective propert...

Starting from explicitly correlated wavefunctions, the one-body momentum density, γ ( E p), and the expectation values 〈δ( E p)〉 and 〈pn〉, with n = −2 to +3, have been obtained for the atoms helium to neon. All the calculations have been carried out by using the Monte Carlo algorithm. An analysis of the numerical accuracy of the method has been performed within the Hartree– Fock framework. The ...

We study the spin-ordering and the magnon collective modes of the twodimensional Wigner crystal state at strong magnetic fields. Our work is based on the Hartree-Fock approximation for the ground state and the timedependent Hartree-Fock approximation for the collective modes. We find that the ground state is ferromagnetic, i.e., that all spins are aligned at T = 0 even when the electronic g-fac...

We present exact Hartree–Fock–Bogoliubov calculations with the finite range density dependent Gogny force using a triaxial basis. For the first time, all contributions to the Pairing and Fock Fields arising from the Gogny and Coulomb interactions as well as the two-body correction of the kinetic energy have been calculated in this basis. We analyze the relevance of these terms in different regi...