Ground state properties of SiC, AlN, GaN and InN in the zinc-blende and wurtzite structures are determined using an ab initio scheme. For the selfconsistent field part of the calculations, the Hartree-Fock program Crystal has been used. Correlation contributions are evaluated using the coupledcluster approach with single and double excitations. This is done by means of increments derived for lo...

This paper presents the formulation and numerical implementation of a self-consistent treatment of orbitaldependent exchange-correlation functionals within the projector-augmented-wave method of Blöchl [Phys. Rev. B 50, 17953 (1994)] for electronic structure calculations. The methodology is illustrated with binding energy curves for C in the diamond structure and LiF in the rock salt structure,...

Results of detailed calculations for SrTiOs (100) surface relaxation and the electronic structure for the two different terminations (SrO and TiO2) are discussed. These are based on ab initio Hartree-Fock (HF) method with electron correlation corrections and Density Functional Theory (DFT) with different exchange-correlation functionals, including hybrid (B3PW, B3LYP) exchange techniques. Resul...

Exciton effects on conjugated polymers are investigated in soliton lattice states. We use the Su-Schrieffer-Heeger model with long-range Coulomb interactions. The Hartree-Fock (HF) approximation and the single-excitation configurationinteraction (single-CI) method are used to obtain optical absorption spectra. The third-harmonic generation (THG) at off-resonant frequencies is calculated as func...

Hartree-Fock (HF) and Density Functional Theory (DFT) methods employed to study the effect of conformational change on the 13C chemical shifts of 6-mono axial and equatorial substituted and 6,7-di axial-axial, equatorial-equatorial and axial-equatorial substitutedderivatives of 5,6,7,8-tetrahydrodibenzo[a,c]cyclo-octene. The geometry of the conformers have been optimized...

Within the Hartree-Fock approximation the ground state of the composite fermion metal is found. We observe that the single-particle energy spectrum is dominated by the logarithmic interaction exchange term which leads to an infinite jump of the singleparticle energy at the Fermi momentum. It is shown that the Hartree-Fock result brings no corrections to the RPA Fermi velocity.

Spontaneous fission barriers, quadrupole inertia, and zero-point quadrupole-energy corrections are calculated for 252,256,258 Fm in the framework of the self-consistent Skyrme-Hartree-Fock+BCS theory. Two ways of computing dynamical inertia are employed: the Gaussian Overlap Approximation to the Generator Coordinate Method and crank-ing ansatz. The Skyrme results are compared with those of the ...

The Daejeon16 two-nucleon interaction is employed in many-body approaches based on the mean-field approximation. perturbative character of verified by comparing results for 16O from Hartree-Fock (HF) approximation and no-core shell model examining magnitude corrections to HF energy light heavy nuclei. In order approximately describe energies radii across nuclear chart, a phenomenological correc...

We have used the Hartree-Fock Random Phase Approximation (HFRPA) to study the interacting electron gas in a quantum wire. The spectra of intersubband spin-flip excitations reveal a considerable red shift with respect to single-particle HF energies. That signals on appearance of collective intersubband spind-density excitations due to the exchange interaction. The long wavelength dispersions of ...