Showing papers by "Ernest R. Davidson published in 1967"
TL;DR: In this paper, a general method for carrying out population analysis of wavefunctions calculated with arbitrary basis sets is presented, and the difficulties in defining orbital populations are discussed, and results are presented for the sequence BF, CO, and N2 which indicate that back transfer of charge in the π bond cancels the normal transfer of the charge in σ bond.
Abstract: A general method for carrying out population analysis of wavefunctions calculated with arbitrary basis sets is presented. The difficulties in defining orbital populations is discussed. Results are presented for the sequence BF, CO, and N2 which indicate that back‐transfer of charge in the π bond cancels the normal transfer of the charge in the σ bond. Contrary to popular belief, the more electronegative element has the larger degree of hybridization in each case. The amount of promotion of 2s electrons is greater on the less‐electronegative element, as expected.
313 citations
TL;DR: In this paper, the low-lying electronic states of the Be2 molecule have been examined using MO SCF CI with a basis set of elliptical orbitals, and the ground state of the molecule was found to be repulsive in the best calculation.
Abstract: The low‐lying electronic states of the Be2 molecule have been examined using MO SCF CI with a basis set of elliptical orbitals. The ground state of the molecule was found to be repulsive in the best calculation. The excited states all seem to be bound with potential curves similar to that predicted for Be2+. Two new techniques for improving the convergence of configuration interaction are introduced and applied to the ground‐state calculation.
111 citations
TL;DR: In this paper, a naturalorbital configuration interaction calculation was carried out on the ground state of the hydrogen fluoride molecule at the experimental equilibrium internuclear separation (1.7328 a.u.).
Abstract: A natural‐orbital—configuration‐interaction calculation has been carried out on the ground state of the hydrogen fluoride molecule at the experimental equilibrium internuclear separation (1.7328 a.u.). A non‐relativistic energy of −100.2577 a.u. was obtained with 39 configurations. Individual pair correlation energies totaling to over 80% of the total correlation energy were obtained by considering double excitations of each pair.
72 citations
TL;DR: In this paper, the low-lying electronic states of the B2 molecule have been investigated using configuration interaction and the lowest state was found to be the 5 Σu− (−49.14567 hartrees at re=2.95 bohrs.
Abstract: The low‐lying electronic states of the B2 molecule have been investigated using configuration interaction. Eighty‐one states were considered and the lowest state was found to be the 5Σu− (−49.14567 hartrees at re=2.95 bohrs.
58 citations
57 citations
TL;DR: In this paper, the Condon parabola was used to test the validity of the Franck-Condon prineiple within the Born-Oppenheimer approximation for the transition from the ground-electronic state (1 Σ g + ) to the 1 s 2 p, 3 p, and 4p 1 Π u excited states.
56 citations