The ground-state geometry of the NiC3 and NiC4 clusters is investigated using accurate ab initio methods and compared with predictions using the tight-binding molecular-dynamics ~TBMD! method as well as the density functional theory ~DFT! based SIESTA method. The ab initio methods predict the ground-state geometry of the NiC3 cluster to have a rhomboidal geometry, in agreement with the TBMD met...

In this paper, we generalize the definitions of approximately inner $C_0$-groups and their ground states to the two- parameter case and study necessary and sufficient conditions for a state to be ground state. Also we prove that any approximately inner two- parameter $C_0$--group must have at least one ground state. Finally some applications are given.

Ab initio electronic structure theory has been applied to predict the structures and electronic spectra of free-base porphyrin (PH2) and its meso-tetrahalogenated derivatives (m-PX8H2; X = F, Cl, Br). Structures, singlet-triplet energy gaps, and electronic spectra are predicted using the B3LYP method in conjunction with the 6-31G(d) basis set and the effective core potentials/basis sets of Stev...

This paper reports the observation of autodetaching resonances in photoelectron spectroscopy of Au according to the process Au2 + hv=:> (Aur ) * => Au 2 + e . They appear as sharp features superimposed upon a nearly constant signal associated with direct photodetachment process from Aur :Au + hv=>Au2 + e . By altering the cluster expansion conditions, the dimer anion temperature can be varied. ...

The transport spectrum of a strongly tunnel-coupled one-electron double quantum dot electrostatically defined in a GaAs/AlGaAs heterostructure is studied. At finite source-drain-voltage we demonstrate the unambiguous identification of the symmetric ground state and the antisymmetric excited state of the double well potential by means of differential conductance measurements. A sizable magnetic ...

Single 9.6 fs deep ultraviolet pulses with a spectral range of 255-290 nm are generated by a chirped-pulse four-wave mixing technique for use as pump and probe pulses. The electronic excited state and vibrational dynamics are simultaneously observed for an aqueous solution of uracil and thymine over the full spectral range using a 128-channel lock-in amplifier detector. Two probe photon energy-...

The methods producing cold molecules from cold atoms tend to leave molecular ensembles with substantial residual internal energy. For instance, cesium molecules initially formed via photoassociation of cold cesium atoms are in several vibrational levels nu of the electronic ground state. We applied a broadband femtosecond laser that redistributes the vibrational population in the ground state v...

From relativistic quantum-chemical calculations of the molecular electronic structure of hydrogen iodide HI in electronic state X S or 0 using the Dirac–Coulomb coupled-cluster method with singles, doubles and noniterative triples (DC-CCSD(T)), we have evaluated the electric dipole moment p at 17 values of internuclear distance R. On this basis we have calculated the pure vibrational expectatio...

The low-lying electronic states of yttrium dicarbide have been calculated using highly correlated wave functions and systematic sequences of correlation consistent basis sets. For the (2)A(1) ground electronic state, the near-equilibrium potential energy surface (PES) has been calculated using the coupled cluster method in conjunction with basis sets ranging in size from double to quintuple zet...

We report on a novel ultrafast two-dimensional infrared laser experiment that correlates vibrational bands of reactant and product of a photoreaction. The possibilities of this technique are demonstrated for the metal-to-ligand charge transfer (MLCT) in [Re(CO)3Cl(dmbpy)] (dmbpy = 4,4'-dimethyl-2,2'bipyridine) where we correlated the CO vibrational modes of the ground state and the MLCT state. ...