The electronic structure for a representative late-transition-metal-methylene complex, Ru=€H2+, has been studied by ab initio methods (generalized valence bond/configuration interaction). The electronic-state spectrum reveals five states close in energy (spread of 12.9 kcal/mol) that partition into two groups in terms of energy separation and mode of metal-carbon bonding. The ground state has *...

A treatment of oneor two-photon fluorescence excitation spectra is described using the vibration-rotation coupling of zeroth order states in the excited electronic state and nonadiabatic coupling to the ground state. Using perturbation theory, experimental harmonic frequencies, an anharmonic force field, and various theoretical Coriolis coupling constants, a quasistationary molecular eigenstate...

A breakdown of the standard Watson-type rotational Hamiltonian was suggested for a molecule with H2XYZ structure [Š. Urban and K. M. T. Yamada, J. Mol. Spectrosc. 160, 279–288 (1993)] . This breakdown is due to a near-resonant interaction between the ground state rotational levels and rotational levels in an excited vibrational state. This interaction has been observed in the excited electronic...

The dissociation energies of all rotation-vibrational states of the molecular HD in the ground electronic state are calculated to a high accuracy by including nonadiabatic, relativistic alpha(2), and quantum electrodynamic alpha(3) effects, with approximate treatment of small higher order alpha(4), and finite nuclear size corrections. The obtained result for the ground molecular state of 36 405...

First principles calculations show that the neutral U@C28 has a (cage)(2) ground state with Td symmetry instead of the long believed (5f)(1)(cage)(1) ground state with D2 symmetry. Its 34 valence electrons preferentially obey the 32-electron principle which fills all the s-, p-, d-, and f-type valence shells of the uranium atom. The remaining two valence electrons cannot break the electronic co...

We study the effect of tunneling on the electronic structure of two vertically coupled quantum rings within the spin density functional theory. The ground state configurations of the coupled rings are obtained for a system with 10 electrons as a function of the ring radius and the inter-ring distance. For small ring radius, our results recover those of coupled quantum dots. For large ring radiu...

The ground and low-lying electronic states of the 1,3,5-tridehydrobenzene triradical are characterized by electronic structure calculations. It is found that the ground state is the A1 doublet of C2v symmetry. Another doublet state lies 0.1–0.2 eV higher in energy, and the lowest quartet state of D3h symmetry is 1.2–1.4 eV higher in energy. Both doublets are degenerate at D3h geometries and und...

We discuss the production of ultracold molecules in their electronic ground state by photoassociation employing electronically excited states with ion-pair character and strong spin-orbit interaction. A short photoassociation laser pulse drives a nonresonant three-photon transition for alkali-metal atoms colliding in their lowest triplet state. The excited-state wave packet is transferred to th...

Ab initio complete active space SCF calculations have been carried out to investigate the first excited electronic state of a retinal protonated Schiff base analog: all-trans-3,7-dimethylnona-2,4,6,8-tetraenmethylimminium cation. This model of the retinal chromophore in bacteriorhodopsin includes five conjugated double bonds as well as both pertinent backbone methyl groups. The excited state mi...

We report high-resolution anion photoelectron spectra of vanadium dioxide (VO2 (-)) obtained by slow electron velocity-map imaging of trapped and cryogenically cooled anions. Vibrationally resolved spectra are obtained for photodetachment to the first three neutral electronic states, giving an electron affinity of 1.8357(5) eV for the X̃A12 ground state and term energies of 0.1845(8) eV and 0.81...