Using ab initio unrestricted Hartree−Fock, restricted open-shell Hartree−Fock, and fourth-order perturbation theory methods, 13 minima on the Si2CH4+ potential energy surface have been calculated including ion−molecule complexes, Si−H and C−H insertion products, and other Si2CH4+ isomers. The transition states connecting those isomers have been located and the minimum energy paths have been tra...

The spherical Hartree-Fock approximation is applied to the ab initio no-core shell model, with a realistic effective nucleon-nucleon interaction in order to investigate the range of its utility. Hartree-Fock results for binding energies, one-body density distributions and occupation probabilities are compared with results from exact diagonalization in similar model spaces. We show that this mea...

The angular distributions of photoelectrons from atomic oxygen, nitrogen and carbon are calculated. Both Hartree-Fock and Hartree-Slater (Herman-Skillman) wave functions are used for oxygen, and the agreement is excellent; thus only Hartree-Slater functions are used for carbon and nitrogen. The pitch angle distribution of photoelectrons is discussed and it is shown that previous approximations ...

We propose a mean field framework in which the charge and the parity symmetries of a single-particle state are broken. We break these symmetries to incorporate the correlation induced by the tensor force into a nuclear mean field model. We perform the chargeand the parity projections before variation and obtain a Hartree-Fock-like equation (chargeand parity-projected Hartree-Fock equation), whi...

Basis set convergence of the Hartree-Fock and the correlation energy is examined for the hydrogen bonded infinite bent chains (HF)∞ and (HCl)∞. We employ series of correlation consistent basis sets up to quintuple ζ quality together with a coupled cluster method (CCSD) to describe electron correlation on ab initio level. The Hartree-Fock energy converges rapidly with increasing basis set qualit...

The general construction of semiclassically concentrated solutions to the Hartree type equation, based on the complex WKB-Maslov method, is presented. The formal solutions of the Cauchy problem for this equation, asymptotic in small parameter ( → 0), are constructed with a power accuracy of O( N/2), where N is any natural number. In constructing the semiclassically concentrated solutions, a set...

The phase diagram of the Schwinger model on the lattice with one and two degenerate flavours of Wilson fermions is investigated in the Hartree-Fock approximation. In case of a single flavour (not directly amenable to numerical simulation), the calculation indicates the existence of the parity violating phase at both weak and intermediate-to-strong couplings. In the broken phase, the Hartree-Foc...

The phase diagram of the Schwinger model on the lattice with one and two degenerate flavours of Wilson fermions is investigated in the Hartree-Fock approximation. In case of a single flavour (not directly amenable to numerical simulation), the calculation indicates the existence of the parity violating phase at both weak and intermediate-to-strong couplings. In the broken phase, the Hartree-Foc...

The quantum hadrodynamics are studied by using non-perturbative renormalization group equations. Approximate discrete γ5-symmetry is studied. It is shown that the contributions of one-loop diagrams are important for effective potential. A relation between the local-potential approximation and the usual Hartree approximation is discussed. The local-potential approximation includes contribution o...