Showing papers in "Chemical Physics in 1987"

TL;DR: In this article, the Hartree-Fock wavefunctions were used to recover up to 88% of the correlation energy of the H 2 O electron momentum spectroscopy measurements.

TL;DR: In this article, the cross sections for photo absorption and photodissociation of CO between 88.5 and 115 nm have been measured at a spectral resolution of 0.015 nm using a synchrotron radiation source.

TL;DR: In this paper, the kinetics of intramolecular photoinduced electron transfer in a series of pyromellitimide-bridge porphyrins have been studied using transient absorption and fluoresence techniques.

TL;DR: In this paper, the convergence properties of the Moller-Plesset dispersion energy with respect to saturation of polarization basis set have been investigated, by means of the partial wave expansion through “i” terms, for the He dimer.

TL;DR: In this paper, the Bloch transformation is used to decompose the time-dependent Schrodinger equation and to construct an effective evolution with the BLoch effective hamiltonian, which is calculated in a tight-binding approximation as a function of the number of ligand active units.

TL;DR: In this article, the Gin-Hartree approach was shown to be the optimal model for the short-range correlation potential, especially if the self-interaction is not explicitly eliminated.

TL;DR: In this paper, an efficient vectorised procedure for the calculation of dipole moment derivatives at the closed-shell MP2 level of accuracy is described, and the formalism for the calculated MP2 gradients is also given as it is shown that the dipole moments derivatives can be handled in a very similar manner.

TL;DR: In this article, the TSH method is used to compute product cross sections for the reactions H+ + D2, D++ D2 and D+ + H2, which are compared with integral cross sections obtained with a guided beam apparatus.

TL;DR: In this paper, a new mechanism for the rapid initial charge separation in bacterial reaction centers is investigated, which can be characterized as a combined exciton-electron transfer mechanism, which involves as first step the deactivation of the initially excited dimer (BCLPBCMP*) together with a charge transfer transition between the accessory monomer BCLA and the pheophytine BPL leading to the state BC+LABP−L. This first step is followed by a rapid electron transfer from the dimer to the cation BC+LA.

TL;DR: The chemical electronegativity of an atom (Mulliken definition) has been identified with the average value of χ with respect to the density functional theory as discussed by the authors, and an appropriate definition of hardness is developed, and a scale of hardness for bonded atoms is proposed.

TL;DR: In this paper, the long-range energy matrix elements have been calculated in the multipolar expansion approximation for all the molecular states dissociating to the three or four lowest asymptotes for the molecules LiNa, LiK, LiRb, LiCs, NaK, NaRb and NaCs, KRb, KCs and RbCs using the semi-empirical perturbative model.

TL;DR: In this paper, the rotational contours of the binary van der Waals (vdW) spectra of aniline with rare gas atoms (He, Ne, Ar, and Kr) in a supersonic free jet were analyzed to determine the geometrical structures.

TL;DR: In this paper, it is suggested that the regression path is determined by a few simple rules, i.e., an initial conservative-type distribution of information over a self-similar hierarchy, which is superceded eventually by a dissipative process which also proceeds in a selfsimilar manner.

TL;DR: In this paper, a two-quantum multiple pulse sequence with a 90° phase shift was used for spin clustering in thermal equilibrium NMR with a spin system in dipolar coupled NMR.

TL;DR: In this article, the dissociation spectra of NH3 clusters have been recorded using a cw CO2 laser and two absorption bands have been found at 979 and 1004 cm−1, which originate from the excitation of two nonequivalent NH3 molecules.

TL;DR: Part of a photoelectron band assigned to the phenyl radical, produced from the F + C6H6 reaction, has been recorded in this article, where the adiabatic ionization energy was measured as 8.32±0.04 eV.

TL;DR: In this article, high-resolution electron energy loss spectra of the sulfur 2p, 2s and oxygen 1s inner shells of SO 2 have been obtained under conditions of high impact energy (1-3 keV) and zero-degree scattering angle.

TL;DR: In this paper, a time-correlated photon-counting technique was used to estimate the decay time of pyrene crystals over the temperature range 295−136 K (above the phase transition point) and the lower bound of the time required for excitons to tunnel through the barrier was estimated to be 36 ps.

TL;DR: In this paper, the radiative decay of the fluorescence excited by a pulsed laser has been used to measure radiative lifetimes of excited electronic states of the isovalent CuF and CuCl diatomic molecules.

TL;DR: In this paper, the authors applied the previously formulated "rotational sliding mass model" (RSMM) to the nearly thermoneutral reaction O( 3 P) + HCl → OH + Cl in a quasiclassical trajectory.

TL;DR: In this paper, the rate constants k on the reaction free energy Δ G are characterized by a rapid increase with exothermicity at small − Δ G and almost constant maximum values at high excess energy, where the actual energy transition step in case of an encounter is taken as a radiationless process in the supermolecule consisting of the reactants and the solvent environment.

TL;DR: In this article, a large Gaussian basis set augmented by three d-type polarization functions on each carbon center is used to approximate the molecular orbits, and ab initio calculations of the X 1 Σ + g and a 3 II u states of C 2 are performed to determine the corresponding potential curves around the potential minima and at dissociation limits.

TL;DR: In this article, the authors reported a detailed assignment of photoexcitation and partial-channel photoionization processes in the valence shell of H 2 S employing single-and coupled-channel, vertical-electronic, static-exchange approximations.

TL;DR: In this article, the transformation properties of the Mueller matrix on application of certain spatial symmetry operations, partially combined with reversal of motion, to the sample (including the fields) can be given explicitly.

TL;DR: In this paper, the vibrational Raman Stokes spectrum of C2H6 was measured from 600 to 6500 cm−1 using the powerful focused radiation of a free running Ar-ion laser.

TL;DR: In this article, it was shown that for a new class of polymers, ferromagnetic superexchange may arise, which depends strongly on the energy gap of the delocalized π-electron system.

TL;DR: In this article, the recombination probability of radical pairs was calculated for several models of RPs and the relationship between the recombinations and the Larmor frequencies of the unpaired electrons of the two radicals of the pair was analyzed.

TL;DR: In this paper, the amplification of weak asymmetric advantage factors (AF) in simple (non-cooperative) and cooperative systems containing mirror isomers is discussed, and it is shown that the amplification mechanisms in cooperative systems near the critical point and in simple systems are identical.

TL;DR: In this paper, fluorescence line-narrowing experiments on low-temperature molecular crystals composed of hydrogen-bonded dimers of benzoic acid were conducted.

TL;DR: In this article, the first 6 2 Σ + g adiabatic potential energy curves of He + 2 were calculated with the MRD CI method employing configuration selection (T = 10 μ hartree) and perturbative energy corrections and using two basis sets differing in the number of diffuse functions.