Showing papers by "Adrian E. Roitberg published in 1996"
TL;DR: In this paper, the current vs voltage curves of a mesoscopic device consisting of two electrodes and a molecular wire were studied at the Hartree-Fock level with electron repulsion.
Abstract: We have studied the current vs voltage curves (I–V characteristics) of a mesoscopic device consisting of two electrodes and a molecular wire. The wire Hamiltonian includes both electronic tunneling and Coulomb repulsion within a Hubbard model that is treated at the Hartree–Fock level. The inclusion of electron repulsion is an extension of our previous work that only considered the case of noninteracting electrons. We have found several important features in the calculated characteristics of the wire. These include (1) a staircaselike structure that strongly resembles that associated with Coulomb blockade in heterostructures and quantum dots, but that in the case of the wire is associated with the discrete nature of the molecular resonances; (2) regions of negative differential resistance associated with increased localization of the molecular resonances. Our theoretical model includes a consistent treatment of the conduction in the linear and nonlinear regimes which remains valid even when the device is o...
294 citations
TL;DR: In this paper, the Mo/ller-ller-plesset perturbation theory is employed to improve the accuracy of static mean field computations in molecular vibration problems, which is a simple and efficient way to get nearly exact frequencies for few-mode model potentials.
Abstract: Mo/ller–Plesset perturbation theory is employed to improve the accuracy of static mean field computations in molecular vibration problems. This method is a simple and efficient way to get nearly exact frequencies for few‐mode model potentials. For more realistic potentials representing the dynamics of water and formaldehyde, the Mo/ller–Plesset treatment works equally as well. However, we find in general that MP2 level corrections give very accurate energies and additional corrections by higher level terms in the MP series are not substantial. Moreover, we find that for reference states on high energy manifolds degeneracies can result when higher level terms are included in the series. We discuss several ways to remove these degeneracies.
228 citations
TL;DR: In this paper, the authors studied the properties of molecular wires with respect to disorder and to increased electronic connectivity and found that the distribution of conductances is lognormal, the parameters of which depend on disorder and on connectivity.
Abstract: Molecular wires are studied with respect to disorder and to increased electronic connectivity. We find that, with increased connectivity, the tendency to exhibit sharp changes of the conductance with modifications of the bridge structure is reduced. We find that the conductance falls off exponentially with distance for injection energies below the bridge energy band, and shows quantum behavior (oscillatory with wire length) for injection in the band. With disorder, we find that the distribution of conductances is lognormal, the parameters of which depend on disorder and on connectivity.
104 citations