Leif Laaksonen

Two-dimensional, fully numerical molecular calculations. X: Hartree-Fock results for He2, Li2, Be2, HF, OH−, N2, CO, BF, NO+ and CN−

Fully numerical two-dimensional Hartree-Fock calculations are reported for the ground states of the diatomic systems He2, Li2, Be2, HF, OH-, N2, CO, BF, NO+ and CN-. total energies, electric multipole moments and electric field gradients are given. A close agreement with the seminumerical results by McCullough is obtained. High multipole moments, up to Q 10, are reported and compared to LCAO ones. The role of correlation in nuclear quadrupole coupling constants is discussed.

A Numerical Hartree-Fock Program for Diatomic Molecules

This paper describes an algorithm and a computer program which solves numerically (virtually exactly) equations of the restricted open-shell Hartree-Fock and Hartree-Fock-Slater model for diatomic molecules

Nuclear quadrupole moment of lithium from combined fully numerical and discrete basis-set calculations on LiH

Abstract The electric field gradients at the nuclei in LiH are calculated by combining fully numerical and discrete basis-set methods. The earlier calculations are shown to contain substantial basis-set truncation errors. The present lithium quadrupole moments are Q ( 6 Li) = −0.00083 b and Q ( 7 Li) = −0.0406 b.

Nuclear quadrupole moment of nitrogen from combined fully numerical and discrete basis-set calculations on NO+ and N2

Abstract The electric field gradients at the nuclei in NO + and N 2 are calculated by combining fully numerical and large-basis LCAO methods. The Q ( 14 N) values from the two molecules are consistently equal to 0.0205 b, as compared with the current value of 0.0193(8) b from N + 2p3p 1 P 1 .

Two-dimensional fully numerical solutions of molecular Hartree-Fock equations: LiH and BH

Abstract A fully numerical Hartree-Fock approach is developed for diatomic molecules. The exchange potential is solved relaxing a local, Poisson-like equation. Improved Hartree-Fock limits are reported for LiH and BH.

Molecular dynamics simulations of the water/octanoate interface in the presence of micelles

Abstract Molecular dynamics (MD) simulations have been used to study structural and dynamical aspects of a sodium octonoate micelle. The model micelle contains 15 octanoate molecules and 15 sodium atoms in an aqueous solution containing 792 water molecules in a cubic 31.1 A box. The coordinate trajectory from a 300 ps simulation has been used to analyze the hydrophobic core region, the distribution of counter ions and water molecules around the monomer head groups. Of special interest is to investigate the mechanism of water penetration into the hydrophobic hydrocarbon core region. The results are discussed in relation to some recent findings on the properties of medium-chain surfactants.

Two-dimensional fully numerical solutions of molecular Dirac equations. One-electron molecules

Abstract A fully numerical two-dimensional approach is presented for the electronic Dirac equation of linear molecules. The method is tested on the lowest S 1/2 state of H and σ 1/2 states of H 2 + and HeH 2+ .

Two-dimensional, fully numerical solutions of second-order Dirac equations for diatomic molecules. part 3

The exact, four-component second-order Dirac equation in transformed elliptical coordinates is derived for a diatomic system. Numerical solutions are obtained using a point-relaxation approach. The relativistic correction to the total energy of H2+ at R = 2a.u. is found to be −7.365 × 10−6a.u. The deviation from an earlier value of −7.383 × 10−6a.u. by Luke et al. or by Bishop is shown to arise from a spuriously large c−4 term in their Hamiltonian.

Fully numerical hartree-fock calculations on the third-row diatomics AlF, SiO, PN, CS, BCl, SH- and P2

Abstract Total and orbital energies and multipole moments calculated by the fully numerical Hartree-Fock method are reported for the third-row diatomic molecules A1F, SiO, PN, CS, BCl, SH- and P 2 and for the Ar atom. The total energies agree within 3–10 mhartree with the best results calculated by the LCAO Hartree-Fock method using Slater-type orbitals. The experimentally unknown dipole moment of BCl is determined to be 1.46D (B − Cl + ) and the deuteron quadrupole coupling constant of SD − to be 180 kHz.

TWO-DIMENSIONAL FULLY NUMERICAL MC SCF CALCULATIONS ON H2 AND LiH: THE DIPOLE MOMENT OF LiH

Abstract A multiconfiguration version of the two-dimensional fully numerical Hartree-Fock method is presented and applied to H2 and LiH. In combination with CAS SCF LCAO results, a dipole moment of 2.310(4) au is obtained for LiH(ν = 0, J = 1) (expt. 2.3141(2)).