Showing papers in "Chemical Physics in 2000"

TL;DR: In this article, it is shown that the empirical potential structure refinement procedure, which attempts to fit a three-dimensional ensemble of water molecules to all three partial structure factors simultaneously, leads to improved reliability in the extracted radial distribution functions.

TL;DR: In this article, a pump-pump-probe technique was introduced which allows to study hot electron relaxation by probing the reflectivity in thermal equilibrium between electrons and lattice.

TL;DR: In this paper, a theoretical analysis of the sum frequency generation (SFG) spectrum of the water surface in the OH stretch mode frequency region based on ab initio molecular orbital theory and molecular dynamics simulation is provided.

TL;DR: In this article, the pump-probe signals near the plasmon resonance of the nanoparticles reveal the importance of electron-electron scattering during several hundreds of femtoseconds.

TL;DR: In this article, the authors decompose a molecular dynamics (MD) trajectory of 1.5 ns for a C-phycocyanin dimer surrounded by a layer of water into three contributions that are expected to be independent: the global motion of the residues, the rigid-body motion of sidechains relative to the backbone, and the internal deformations of the sidechains.

TL;DR: In this article, the exciton states in quasi-one-dimensional organic crystals with strong orbital overlap between neighboring molecules were considered and a Hamiltonian model was proposed to explain the main features of the low temperature absorption spectra.

TL;DR: In this article, the equilibrium constant for autodissociation of water is computed by imposing constraints on proton coordination number in an ab initio molecular dynamics simulation of the liquid.

TL;DR: In this article, the structural characteristics and relative stabilities of different isomers as well as electron affinities and vertical detachment energies are calculated using two exchange-correlation functionals, local spin density approximation and spin-polarized Becke-Lee-Yang-Parr (BLYP).

TL;DR: In this article, it is found that the hydrogen bonding is enhanced in the confined state and the nucleation temperature is depressed, which is due to formation of an extended hydrogen-bonded network similar to that of amorphous ice.

TL;DR: In this article, the ultrafast surface plasmon resonance nonlinearities and their connection with the conduction band electron dynamics are discussed in metal nanoparticles in the light of the results of high sensitivity femtosecond pump-probe experiments in silver nanoparticles embedded in a glass matrix.

TL;DR: In this paper, the authors present experimental evidence for resonant tunneling of electrons at surfaces in the time regime ranging from sub-femtoseconds to (sub)-femtoconds.

TL;DR: In this article, a twin state model was proposed for linear conjugated polyenes, which represented the ground state (S 0 ) and first excited state(S 1 ) as a superposition of mainly two mesomeric structures, the fully spin-paired one and a diradical.

TL;DR: In this article, a quasi-classical dynamical approach was used to calculate the global dissociation rate of nitrogen atoms with rovibrationally excited nitrogen molecules, relative to the whole set of vibrational states and interpolated on rotation, including quasi-bound levels.

TL;DR: In this article, nano-assembled model catalysts consisting of size-selected metal clusters (Aun, Ptn, Pdn, and Rhn, n=1-20), supported on thin MgO(1−0-0) films, reveal distinct size-effects.

TL;DR: In this article, the authors compare the geometries and relative energies of important secondary structural elements, the 3.613 helix, 310 helix and C5ext structures, for a set of blocked peptide models, N-acetyl-( L -alanyl)n-N′-methylamide, for n=1-20.

TL;DR: In this paper, the authors studied the dynamics of water molecules at the surface of a C-phycocyanin protein by high resolution quasi-elastic neutron scattering and showed that the relaxation times of interfacial water exhibit a power law dependence on the wave vector Q.

TL;DR: In this paper, the authors used molecular beam techniques to create nanoscale thin films composed of different isotopes of amorphous solid water (ASW) composites and determined the extent of isotopic intermixing using temperature programmed desorption.

TL;DR: In this article, the potential energy of LiRb and NaRb molecules has been calculated over a wide range of internuclear distances for the 28 lowest molecular states, using an ab initio method based on nonempirical pseudopotentials, parametrized l-dependent polarization potentials and full valence configuration interaction calculations.

TL;DR: The spectral evolution of myoglobin (Mb) following the Soret band (S) excitation (405 nm) was measured in the Q-band (450-630 nm) and band-III (730-900 nm) regions as discussed by the authors.

TL;DR: In this paper, the efficacy of several DFT and HF-DFT methods for the calculation of 14 N quadrupole coupling constants in molecules has been investigated by linear regression analysis of the calculated efg's versus the experimental nqcc's.

TL;DR: In this paper, the rotationally resolved S 1 ←S 0 electronic spectrum of the hydrogen-bonded phenol-methanol cluster has been analyzed and the threefold barriers to internal rotation of the methyl group in the methanol moiety were determined.

TL;DR: In this paper, the macroscopic first-to third-order susceptibilities of naphthalene, anthracene and meta-nitroaniline (mNA) were calculated using a rigorous local field approach.

TL;DR: In this paper, the authors show that the first two steps correspond to relaxation along a Jahn-Teller active coordinate and internal conversion between metal-to-ligand charge transfer states via a JT induced conical intersection, whereas in the third step the molecules change over to a repulsive ligand-field surface and dissociate.

TL;DR: In this paper, the authors present an overview of recent efforts to combine neutron scattering and atomistic simulations in the study of melt dynamics of polyethylene and polybutadiene. And they show how combined results of scattering and simulation can be used to critically test theories that attempt to describe melting dynamics of short polymer chains.

TL;DR: In this paper, the authors measured ultrafast changes in the dielectric function of GaAs over the spectral range from the near IR to the near UV caused by intense 70-fs laser excitation.

TL;DR: In this article, the authors used the perturbative instanton approach to solve the dynamical problem without reducing the number of degrees of freedom, and derived the tunneling path and globally uniform wave functions from the fourth-order Hamilton-Jacobi equation and second-order transport equation.

TL;DR: In this paper, the NIS spectra of the major building blocks of RNA (bases and ribonucleosides) have been recorded in solid phase by means of neutron inelastic scattering (NIS) at low temperature (T = 15 K) for the analysis of vibrational modes in which hydrogen atom motions are involved.

TL;DR: In this article, Frank et al. extended the algebraic model to incorporate higher-order couplings for the Morse oscillators, thus, providing a means to establish an exact quantum-mechanical connection with traditional phase-space descriptions of molecular vibrations.

TL;DR: In this article, photo-physical parameters of rhodamine 6G in a 2-hydroxyethyl-methacrylate methyl-methylamyclic copolymer (volume mixture 1:1) were determined and compared with the same copolymers in methanol, and the photo-degradation under steady-state and pulsed excitation was investigated.

TL;DR: In this paper, the influence of adsorbates on the respective inelastic and quasielastic scattering processes was investigated for Cu on Cu(100) and Cu(111), respectively.