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Showing papers in "Chemical Physics in 1981"


Journal ArticleDOI
TL;DR: In this article, a method is presented which utilizes the calculation of the molecular electrostatic potential or the electric field at a discrete number of preselected points to evaluate the environmental effects of a solvent on the properties of a molecular system.

7,618 citations


Journal ArticleDOI
TL;DR: In this article, the temperature dependence of positron lifetimes in both the brittle and plastic phases of trimethylacetic (pivalic) acid was examined using the positron lifetime technique.

1,640 citations


Journal ArticleDOI
TL;DR: In this article, the point dipole interaction model for molecular polarizability is modified by replacing the point-dipole interaction by an interaction between smeared out dipoles, and rules are developed to indicate plausible forms for this modified interaction.

1,157 citations


Journal ArticleDOI
TL;DR: In this paper, the ionization potential of the complex anions BO 2, AlO 2, NO 3, PO 3, ClO 4, MgF 3, BF 4, AlF 4, SiF 5 −, and PF 6 − were calculated using a self-consistent discrete variational Xα method.

466 citations


Journal ArticleDOI
TL;DR: In this article, the theory of quadratically convergent Hartree-Fock method is developed which is shown to be a simple extension of single excitation CI and closely related to coupled Hartree Fock perturbation theory.

378 citations


Journal ArticleDOI
TL;DR: In this paper, Bounds and Siebrand showed that the electron-hole pair binding energy decreases faster than rCT−1 with increasing separation and explained the high carrier generation efficiency in pentacene.

354 citations


Journal ArticleDOI
TL;DR: In this article, rotational spectra have been assigned for four isotopic species of the linear HCN dimer in the vibrational ground state, and the spectroscopic constants are isotope - B 0 (MHz) D J (kHz) x N 1 (MHz), x N 2 (MHz).

120 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical analysis points to the importance of Fermi resonance in the vibrational relaxation process and quantitatively assess quantitatively its magnitude, because there exist small intensities and shifts of the combination m overtones due to diagonal anharmonicities.

100 citations


Journal ArticleDOI
TL;DR: In this article, two-laser photoinitiation/probe technique has been used to obtain room-temperature second-order rate constants for the reaction of CN radicals with compounds key to atmospheric and combustion chemistry.

93 citations


Journal ArticleDOI
TL;DR: A general kinetic theory for drift-tube experiments on polyatomic ions moving through molecular neutral gases is presented in this paper, where the assumption made about the experimental conditions are discussed and some numerical tests of the theory are presented and discussed.

89 citations


Journal ArticleDOI
TL;DR: In this article, the HOC+/HCO+ potential energy surface has been examined with large basis sets and with incorporation of electron correlation, and the estimated equilibrium structure has re(CO) = 1.155±0.003 A and re(OH) = 0 leading to a J = 1 → 0 rotational transition frequency of 89.0± 0.8 GHz.

Journal ArticleDOI
TL;DR: In this paper, a model based on radiationless excited state transport and trapping by dimers describes the phenomena responsible for fluorescence quenching, and the trapping rate constant is found to have a cubic concentration dependence.

Journal ArticleDOI
TL;DR: In this article, the authors present a theoretical model which allows an estimation of the residence time of a vibrationally excited adsorbate on a surface, and the results are interpreted in terms of Franck-Condon overlaps between the wavefunctions which describe the adorbate-substrate complex and the released adsorbates.

Journal ArticleDOI
TL;DR: In this paper, a new technique for the study of excited state spectra is introduced, which relies on the fully resonant coherent Stokes light generation which is shown to display peaks at excited state vibrational intervals even though there is initially no population in these levels.

Journal ArticleDOI
TL;DR: In this article, self-consistent electron energy distribution functions (edf's) in non-equilibrium nitrogen have been calculated by solving the Boltzmann equation coupled to a system of vibrational master equations including the dissociation process.

Journal ArticleDOI
TL;DR: In this article, the Schrodinger equation for the most general time-dependent hamiltonian being a quadratic form in the operators x and p is reduced to a set of our first order ordinary differential equations.

Journal ArticleDOI
TL;DR: In this paper, an expression for the charge-quadrupole energy WQ was derived for benzene, which includes a macroscopic part, and for naphthalene ∓0.037 eV, for anthracene ∆ 0.168 eV and for biphenyl ∆0.116 eV.

Journal ArticleDOI
TL;DR: In this article, the vibrational and rotational constants for the E excited state have been determined and an RKR potential curve constructed for other excited states in this region, and the isotope effect used to locate electronic origins.

Journal ArticleDOI
TL;DR: In this paper, the ionization spectra of the entire valence region are calculated for HF, HCl, HBr and HI, for the two ionization processes of lowest energy, whereas this picture breaks down for ionization from the inner valence α-orbital.

Journal ArticleDOI
TL;DR: In this article, the authors reported new measurements of the non-exponential fluorescence decay of pyrazine, covering the time range 0.1-200 ns, and showed that the triplet component of the mixed singlet-triplet levels does increase with increasing triplet density of states, and the effective density of triplet levels determined from their experimental data exceeds the theoretical density of vibrational levels.

Journal ArticleDOI
TL;DR: In this article, the thermal distribution of the N 2 and CO 2 molecules over the rotational states is demonstrated, for distances x from the nozzle up to 70 times the nozzle diameter D.

Journal ArticleDOI
TL;DR: In this paper, the 3q-dimensional Fourier transforms of the q-electron charge density and momentum density respectively are defined to be the qelectron form factor and internally folded density.

Journal ArticleDOI
TL;DR: In this article, the energy relaxation of the vibrational 3Σg−(ν = 1) state and the electronic 1Δg(ν′ = 0) state of oxygen in liquid mixtures with Ar and N2 was investigated.

Journal ArticleDOI
TL;DR: In this paper, it was found that the rate of proton transfer decreases more rapidly in water propanol solutions than in water ethanol solutions, which can be interpreted in terms of water breaking structure by the organic solvent.

Journal ArticleDOI
TL;DR: In this paper, the Lippincott-Schroder potentials were used to analyze the vibrational properties of the hydrogen bond systems, including the NH-O and NH-N systems.

Journal ArticleDOI
TL;DR: In this paper, anomalous isotopic effects on the position and the integrated intensity of the v(XH) stretching vibration band of hydrogen-bonded systems have been studied by applying standard methods of non-equilibrium statistical mechanics.

Journal ArticleDOI
TL;DR: In this article, it was theoretically and experimentally shown that steady-state measurements of the angular dependence of the fluorescence depolarization in macroscopically ordered membrane systems form an alternative for fixed-geometry time-resolved experiments in such systems.

Journal ArticleDOI
TL;DR: In this article, the (e, 2e) cross section for electron impact ionization of the hydrogen molecule has been measured with a precision of a few percent at 400 eV incident energy.

Journal ArticleDOI
TL;DR: In this article, a potential energy surface for the O 2 Ar system has been obtained by a multiproperty analysis, including the absolute integral cross sections at thermal energy, the high energy scattering cross sections, the second virial coefficients, and the P and R branches in the absorption infrared spectrum.

Journal ArticleDOI
TL;DR: In this article, photofragment spectroscopy was used to measure the parallel to perpendicular transitions between the ground state and the first excited state in an interval from 300 to 337 nm for KI and NaI and from 265 to 310 nm for kBr and NaBr.