Showing papers in "Chemical Physics in 2008"

TL;DR: In this paper, a molecular dynamics driver and surface hopping algorithm for nonadiabatic dynamics has been implemented in a development version of the MNDO semiempirical electronic structure package.

TL;DR: In this article, a nonadiabatic simulation of photodynamics in pyrazine is presented, where the authors combine time-dependent density functional theory using localized Gaussian basis sets with Tully's stochastic fewest switches surface hopping procedure.

TL;DR: In this article, the authors derived a nonperturbative equation of motion for a reduced system coupled to a harmonic bath with colored noise in which the system-bath coupling operator does not necessarily commute with the system Hamiltonian.

TL;DR: Several variants of coupled electron pair type approximations are compared with respect to their accuracy in the prediction of bond distances, harmonic vibrational frequencies and anharmonic corrections for a range of closed-shell diatomic molecules.

TL;DR: In this paper, an ab initio computational study of various iron porphyrin-type molecules has been performed based on the density functional theory (DFT) and have been conducted usi...

TL;DR: In this article, the excited-state intramolecular proton transfer in the aromatic polycycle 10-hydroxybenzo[ h ]quinoline was investigated by means of transient absorption experiments with 30-fs time resolution, classical dynamics and wavepacket dynamics.

TL;DR: These unique ultrafast quenching pairs, as recently found to extensively occur in high-resolution protein structures, may have significant biological implications.

TL;DR: In this article, a detailed experimental investigation and quantum-chemical analysis of two-photon absorption spectra of symmetrical cationic polymethine and neutral squaraine and tetraone dyes having nearly identical terminal groups and similar conjugation length was performed.

TL;DR: Several computational methodologies rooted into density functional theory (DFT) or Moller-Plesset second order perturbation theory (MP2) have been applied to study the anisole-ammonia and anisoles-water 1:1 molecular complexes in the ground and first excited electronic states, with special reference to the role of dispersion interactions as mentioned in this paper.

TL;DR: In this paper, the validity of several standard quantum chemical approaches and other models for the prediction of exciton energy transfer was investigated using the HOMO-LUMO excited states of benzene dimer as an example.

TL;DR: In this paper, the authors investigated the stability of Fe-doped germanium clusters by using the density-functional approach and found that doping of one Fe atom contributes to strengthening the stability.

TL;DR: In this paper, a third-generation electron momentum spectrometer with significantly improved energy and momentum resolutions at Tsinghua University (ΔE = 0.45-0.68 eV, Δθ = 0,53° and Δϕ= 0.84°) has enabled a reinvestigation of the valence orbital electron momentum distributions of H2O with improved statistical accuracy.

TL;DR: In this paper, the authors report detailed information on the geometry of the hydrogen adsorption sites, based on the analysis of inelastic neutron spectroscopy (INS), which is in agreement with what is found in first principles calculations.

TL;DR: Femtosecond TRIR measurements unambiguously demonstrate that the triplet state is fully formed within the first 10 ps after excitation, ruling out a relaxed (1)npi* state as the tripleT precursor.

TL;DR: In this article, the vibrational Raman optical activity (ROA) spectra for the transition metal complexes Λ-tris(acetylacetonato)cobalt(III), Λ tris (acetylacetyl acetonato), rhodium(III, dichloro-(6R,7S,9S,11S-(−)-sparteine)zinc(II) and Δ(δδ δ)-tris (ethylenediaminato), were calculated.

TL;DR: In this article, a new computational QM method for the study of structural properties (i.e. equilibrium geometry) of molecular systems at very high pressure is presented. But this method is based on the polarizable continuum model (PCM), usually used to study molecular solutes under standard pressure conditions.

TL;DR: An ultrafast flash thermal conductance apparatus is used to study heat flow through aliphatic and aromatic molecules arranged in self-assembled monolayers (SAMs) as mentioned in this paper, which consists of a thin metal film which can be flash-heated by many hundreds of degrees in ∼1-ps using a femtosecond pulse.

TL;DR: A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed.

TL;DR: In this paper, the vertical excitation energies, transition dipole moments and oscillator strengths for a number of astrophysically relevant molecules were calculated using multi-reference configuration interaction.

TL;DR: In this paper, the influence of kosmotropic and chaotropic co-solvents on the hydrogen bonding network dynamics of both bulk water and hydration water was investigated.

TL;DR: In this paper, the structural, electronic, and magnetic properties of Con (n) clusters and their anions have been investigated using the density functional theory with effective core potentials and the generalized gradient correction.

TL;DR: In this paper, a quantum dynamical method is presented to accurately simulate time-resolved nonlinear spectra for complex molecular systems, which combines the nonpertubative approach to describe nonlinear optical signals with the multilayer multiconfiguration time-dependent Hartree theory to calculate the laser-induced polarization for the overall field-matter system.

TL;DR: In this article, the exact time evolution of a general quantum system under the influence of a bosonic bath that causes pure phase noise is derived for a Gaussian initial state of the bath, and the exact result can be obtained also within a perturbative time-local master equation approach.

TL;DR: In this paper, it was shown that these effects are about one or even more than three orders of magnitudes larger than those which may be prepared in oriented planar molecules such as Mg-porphyrin, by means of either circularly polarized laser pulses, or by traditional magnetic fields, respectively.

TL;DR: In this article, the influence of non-denaturing hydrostatic pressure on the relaxation dynamics of lysozyme in solution was investigated. But the results were limited to a time window from about 1 to 100 ps, while its fractal characteristics were preserved.

TL;DR: In this paper, an empirical correlation on the thermal conductivity of the Lennard-Jones fluid based on extensive non-equilibrium molecular dynamics simulations results (103 points) is presented.

TL;DR: From the combination of knowledge and actions, someone can improve their skill and ability and this will lead them to live and work much better.

TL;DR: In this paper, a fast optical multichannel analyzer combined with a non-collinear optical parametric amplifier is used to acquire the differential transmission dynamics on the 500-700 nm wavelength range with sub-10-fs temporal resolution.

TL;DR: In this article, the dynamics of Ribonuclease A were explored in the full range of time and length scales accessible by neutron spectroscopy, on time-of-flight, backscattering and spin-echo spectrometers.