An MCHF atomic-structure package is presented based on dynamic memory allocation, sparse matrix methods, and a recently developed angular library. It is meant for large-scale calculations in a basis of orthogonal orbitals for groups of LS terms of arbitrary parity. For Breit-Pauli calculations, all operators – spin-orbit, spin-other orbit, spin-spin, and orbit-orbit – may be included. For trans...

III. Homonuclear Diatomics: Second-Row Elements 14 A. The diatomic boron molecule 16 1. Σg state 16 2. Σg state 19 B. The diatomic oxygen and carbon molecules in their lowest states 20 1. O2 20 2. Reflection symmetry 21 3. Electron repulsion 23 4. MCSCF calculations for O2 24 5. The C2 molecule 25 C. Spectroscopic notation for diatomic molecules 28 D. States of other homonuclear diatomic molecu...

The vertical transition energies for butadiene have been calculated using the CIS/6-3 1 1 (2+)G* theoretical model. The observed energies were satisfactorily reproduced. The charge distribution for each of the excited states was calculated so that the change from the ground-state distribution could be examined. The nature of the Rydberg states are discussed. Quantitative information on the degr...

Several theoretical methods are employed to characterize the intramolecular proton transfer in the ground state and in the lowest-lying 3nπ∗ and 3ππ∗ excited states of 1-amino-3-propenal. The geometrical parameters, the relative energy of the two tautomeric forms, the energy barrier for the proton transfer, and the energy difference between the ground and the excited states predicted by the dif...

A general theory for response properties is presented which is applicable to perturbations affecting the molecular basis set, notably nuclear derivatives. A perturbation-independent Fock space is introduced, and the necessary reorthonormalization of a truncated basis set after a perturbation is explicitly incorporated in the Hamiltonian. Explicit formulas for MCSCF firstand second-order propert...

Synopsis We present a combined experimental and theoretical study focused on the ionic states of the N2O4 molecule. Experimental results regarding photoionization induced by the synchrotron radiation SOLEIL in the 13.5-15.5 eV energy range were obtained using the electron-ion velocity vector correlation method. The potential energy curves for the dissociation of the N-N bond were computed withi...

Hydrophilic and hydrophobic weak polybasic brushes immersed in aqueous solutions of mixed salt counterions are considered using a mean-field numerical self-consistent field approach. On top of the solvent quality of the polymer, the counterion-solvent interactions are accounted for by implementing Flory-Huggins interaction parameters. We show that ion specificity within the brush can bring abou...

Wolff-Kishner reduction reactions were investigated by DFT calculations for the first time. B3LYP/6-311+G(d,p) SCRF=(PCM, solvent = 1,2-ethanediol) optimizations were carried out. To investigate the role of the base catalyst, the base-free reaction was examined by the use of acetone, hydrazine (H2N-NH2) and (H2O)8. A ready reaction channel of acetone → acetone hydrazine (Me2C=N-NH2) was obtaine...

We present the hamiltonian structures for a wide class of coupled Korteweg-de Vries systems, including the Gear and Grimshaw system that models the strong interaction of internal waves in a stratified liquid and the system of Lou, Tong, Hu and Tang that describes a two layer fluid model. Among the hamiltonian structures of these systems we found new Poisson brackets which define consistent alge...