Showing papers in "Chemical Physics in 1995"

TL;DR: In this article, a model is presented describing the perturbed free induction decay effect for the general situation, where a complex molecule containing many overlapping vibrational modes is investigated, leading to an efficient linear least square fit algorithm allowing the analysis of huge data sets.

TL;DR: In this article, the high-field/high-frequency spin-polarized spectrum of the correlated coupled radical pair P 865 +. after laser flash excitation is a very sensitive monitor of the relative orientation of the two g -matrices and the dipolar tensor with respect to each other.

TL;DR: In this paper, a detailed theory is derived that describes the IR probe signals in three different schemes: pulsed-pump, pulsedprobe spectroscopy, and cw-probe with gating after the sample.

TL;DR: In this paper, the authors compared the behavior of two series of soluble push-pull diphenyl polyenes with respect to the number n of double bonds in the polyenic chain, the exponent value a depending markedly on the end groups.

TL;DR: In this paper, the authors present calculations on near-edge X-ray absorption fine structures (NEXAFS) for pyrene and for molecules in the polyacene series; benzene, naphthalene, anthracene, and tetracene.

TL;DR: The results of large-scale ab initio CI calculations on the electronic states of furan, using a multi-reference multi-root CI method (MRD-CI), are related to new VUV absorption and low-energy electron energy-loss (EEL) measurements, leading to detailed spectral assignments as mentioned in this paper.

TL;DR: In this paper, the competition between superexchange and sequential mechanisms, and the contributions of intermediate bridge states to the propagation from donor to acceptor are addressed by formulating the problem using the density matrix.

TL;DR: In this paper, the formation of H-aggregates as a function of solution, substrate and ambient variables is considered for the merocyanine dye 3-acetyl-5-12-(3-ethyl-2-benzothiazolydene) rhodanine.

TL;DR: In this article, low temperature (10K) absorption, fluoroscence emission, fluorescence excitation, absorption detected magnetic resonance, and microwave induced absorption spectra were recorded together with temperature dependent light induced absorption transients of carotenoid triplet formation and decay in the B800-850 antenna complexes of Rb. sphaeroides 2.4.

TL;DR: In this paper, the first calculations of molecular magnetizabilities using London atomic orbitals at the multiconfigurational self-consistent field level were presented, where a natural connection was introduced to ensure a numerically stable evaluation of the magnetizability.

TL;DR: In this paper, a general approach that considers the Coulomb interactions between the two delocalized electrons, as well as the single and double electron transfer processes which can be operative in delocalization of the electronic pairs is developed.

TL;DR: In this article, the absolute photoabsorption, photoionisation and photodissociation cross sections and the photoionization quantum efficiency of sulphur dioxide have been measured using a double ion chamber and monochromated synchrotron radiation.

TL;DR: In this paper, the authors reported time-resolved transient absorption and gain spectra with subpicosecond laser excitation for weakly polar and highly polar solutions of the merocyanine dye DCM (4-dicyanomethylene-2-methyl-6-(p-dimethylamino-styryl)-4-pyran) in the 380-800 nm spectral range.

TL;DR: In this paper, the hyperfine couplings of the nitrogen nuclei in the radical cations of both 15N-labeled chlorophyll a and the primary donor P700 in Photosystem I of Synechococcus elongatus and spinach (Spinacea oleracea) in frozen solutions were investigated by ENDOR and, for confirmation, by two-dimensional ESEEM techniques.

TL;DR: In this paper, the DF-LCAO method with a DZP-STO basis set has been employed to calculate the energy shifts with respect to CO and the ionization potentials of transition metal carbonyls.

TL;DR: In this article, an accurate electric dipole moment function was calculated for the stretching vibrational coordinates of the linear molecules HCN, HNC, HCCF and HC3N by means of coupled cluster theory with single and double excitation operators plus a quasi-perturbative treatment of connected triples (CCSD(T)).

TL;DR: In this paper, the potential energy surfaces of the water-hydrocarbon complexes H 2 O·CH 4, H 2O·C 2 H 2, H O·C2 H 4 and H O O·H 2 H 4 were examined to locate all the minimum energy structures and estimate the hydrogen bond energies and vibrational frequencies associated with them.

TL;DR: The binding of the primary quinone acceptor, Q, in Photosystem I (PS I) and reaction centres (RC's) of Rhodobacter Sphaeroide-R26 in which, the non-heme iron has been replaced by zinc (Zn-bRCs) is studied using transient EPR spectroscopy.

TL;DR: In this paper, a new computational technique has been developed to simulate charge transport in dilute, energetically random, media, and the results predict that in materials containing 15-20% hopping sites, the transition from field-assisted to field-saturated drift occurs within a field range of 10 5 -10 6 V/cm, lower values referring to lower degrees of energetic disorder.

TL;DR: In this paper, a molecular dynamics simulation using an intermolecular potential where the electrostatic and induction interactions are described with atomic charges, dipole moments and anisotropic dipole polarizability tensors is presented.

TL;DR: In this article, the accuracy of the diatomics-in-molecules (DIM) method is examined for the case of rare gas ionic clusters through a series of careful calibration calculations.

TL;DR: In this paper, the authors compared the Collins-Kimball model with the decay curve calculated numerically using the model incorporating a suitable distance dependence of the reaction rate and found that the model is viable with some reservation.

TL;DR: The results suggest that inhomogeneous broadening and spectral equilibration play a larger role in the early BChl c antenna kinetics in chlorosomes from C. tepidum than in those from C aurantiacus, a system studied previously.

TL;DR: In this article, the authors used femtosecond absorption UV-IR spectroscopy to detect the early charge transfer process triggered by photoexcitation of an aqueous sodium chloride solution (molar ratio H 2 O/NaCl = 55).

TL;DR: In this paper, a series of critical solutions composed of a dipole component (nitrobenzene, o-nitroluene, 1 -nitropropane) and a non-dipole solvent (n -alkanes) are presented.

TL;DR: In this article, it was shown that 20 ± 5% of the excitation energy selectively absorbed by the reaction center pigments in the wavelength region around 830 nm is transferred back to the antenna and gives rise to antenna fluorescence.

TL;DR: In this article, the n=3 excited state was probed using two-photon allowed laser induced fluorescence and a nonlinear least squares regression fits were made between the data and a model calculation using rate equations which describe the population changes for the different angular momentum levels of the n = 3 state.

TL;DR: In this paper, the effects of correlation and relaxation on the calculated momentum profiles are investigated using multi-reference singles and doubles configuration interaction calculations of the full ion-neutral overlap distributions.

TL;DR: In this article, the rate constant for bimolecular reaction between hydrated electrons in the presence of added inert salt was shown to be 6.0 × 10 9 M −1 s −1, virtually independent of added LiClO 4 up to 0.06 M concentration, where the Bronsted-Bjerrum equation would predict a 50% rate enhancement.

TL;DR: In this article, all adiabatic curves of LiH + dissociating into Li(2s, 2p, 3s, 3p,3d, 3d) + H + and Li + + H (1s,2p, 2s and 2p) + were determined by an ab initio approach involving a non-empirical pseudopotential for the Li(ls 2 ) core and core valence correlation corrections.