Showing papers by "Jonathan Tennyson published in 1981"
TL;DR: In this article, the potential energy surface of k-nearest neighbor is generated by ab initio SCF calculations in the region of equilibrium bond distances, and an analytic representation of the surface is presented.
Abstract: The potential energy surface of KCN has been generated by ab initio SCF calculations in the region of equilibrium bond distances. An analytic representation of the surface is presented. The calculations show that the bonding between K and CN is ionic, and that the structure of KCN is triangular, which confirms recent experimental findings. The computed geometry is &KCN = 62.4°, rCK = 5.492a0, and rCN = 2.186a0.
61 citations
TL;DR: In this article, the authors made SCFMO calculations on lithium fluoride clusters both within the crystal and as isolated species, and confirmed the conclusion from perturbation theory that charge transfer is an important contribution to three-body energies and gives a small four-body energy.
Abstract: SCFMO calculations have been made on lithium fluoride clusters both within the crystal and as isolated species. Calculations have been made with different bases in order to separate exchange, charge-transfer and induction energies. Calculations confirm the conclusion from perturbation theory that charge-transfer is an important contribution to three-body energies and gives a small four-body energy. The three-body energies in the crystal environment are much smaller than for the isolated clusters.
23 citations
TL;DR: In this article, an analytic estimate of V 0 is obtained by adding to the near Hartree-Fock curve a function which approximately fits the correlation energy at small R and reduces at large R to the multipolar expansion of the dispersion energy.
16 citations
TL;DR: In this paper, the binding energy of the 2 S state in the unrelaxed lattice of 5·25 eV and a 2 S→2 P transition energy of 4·6 eV was given.
Abstract: SCFMO calculations have been made on the F centre states of LiF using a crystal fragment whose potential closely approximates that of the full crystal. The effect of including electrons of up to third neighbours has been studied. The most extensive calculation gives a binding energy for the 2 S state in the unrelaxed lattice of 5·25 eV and a 2 S→2 P transition energy of 4·6 eV. Lattice relaxation has been calculated in a model appropriate to all lithium halides in which only nearest neighbour electrons are considered. For LiF an outward displacement of nearest neighbour ions by 2·5 per cent of the lattice parameter has been calculated. For the other halides the predicted displacements are smaller.
15 citations