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Showing papers in "Journal of Physical and Chemical Reference Data in 1975"


Journal ArticleDOI
TL;DR: In this paper, the atomic form factor and the incoherent scattering function were derived from available state-of-the-art theoretical data, including the Pirenne formulas for Z=1, configuration-into-action results by Brown using Brown‐Fontana and Weiss correlated wavefunctions for Z =2 to 6 non-relativistic Hartree‐Fock results by Cromer for Z ≥ 0.005 A−1 to 109 A− 1, for all elements A=1 to 100.
Abstract: Tabulations are presented of the atomic form factor,F (α,Z), and the incoherent scattering function, S (x,Z), for values of x (=sin ϑ/2)/λ) from 0.005 A−1 to 109 A−1, for all elements A=1 to 100. These tables are constructed from available state‐of‐the‐art theoretical data, including the Pirenne formulas for Z=1, configuration‐into action results by Brown using Brown‐Fontana and Weiss correlated wavefunctions for Z=2 to 6 non‐relativistic Hartree‐Fock results by Cromer for Z=7 to 100 and a relativistic K‐shell analytic expression for F (x,Z) by Bethe Levinger for x≳10 A−1 for all elements Z=2 to 100. These tabulated values are graphically compared with available photon scatteringangular distributionmeasurements. Tables of coherent (Rayleigh) and incoherent (Compton) total scattering cross sections obtained by numerical integration over combinations of F 2(x,Z) with the Thomson formula and S (x,Z) with the Klum‐Nishina Formual, respectively, are presented for all elements Z=1 to 100, for photon energies 100 eV (λ=124 A) to 100 MeV (0.000124 A). The incoherent scattering cross sections also include the radiative and double‐Compton corrections as given by Mork. Similar tables are presented for the special cases of terminally‐bonded hydrogen and for the H2 molecule, interpolated and extrapolated from values calculated by Stewart et al., and by Bentley and Stewart using Kolos‐Roothaan wavefunctions.

1,606 citations


Journal ArticleDOI
TL;DR: A survey of the electron affinity determinations for the elements up to Z=85 is presented, and based upon these data, a set of recommended electron affinities is established.
Abstract: This article updates a ten‐year‐old review of this subject [J. Chem. Phys. Ref. Data 4, 539 (1975)]. A survey of the electron affinity determinations for the elements up to Z=85 is presented, and based upon these data, a set of recommended electron affinities is established. Recent calculations of atomic electron affinities and the major semiempirical methods are discussed and compared with experiment. The experimental methods which yield electron binding energy data are described and intercompared. Fine structure splittings of these ions and excited state term energies are given.

1,297 citations


Journal ArticleDOI
TL;DR: In this paper, the mean energy and energy distribution of a small number density n of electrons in a gas of much higher number density N is determined by the value of E/N where E is the electric field.
Abstract: An electron swarm consists of a small number density n of electrons in a gas of much higher number density N. The mean energy and energy distribution of such a swarm are determined by the value of E/N where E is the electric field. At any given value E/N the swarm may be characterized by the values of eight parameters, viz; drift velocity, diffusion coefficient. (diffusion coefficient/mobility, excitation coefficient, electron attachment coefficient, electron detachment coefficient, ionization coefficient, recombination coefficient. In this survey, data on these parameters obtained by a variety of experimental techniques are collected, discussed, and compared graphically. Also included on the graphs are computed values of the parameters obtained in many cases from cross sections and energy distributions chosen to give the best fit with the swarm data. Selected tabulations of the data are also given except in cases for which the accuracy of the data is not sufficient to warrant numerical presentation. The ...

518 citations


Journal ArticleDOI
TL;DR: The JANAF Thermochemical Tables cover the thermodynamic properties over a wide temperature range with single phase tables for the crystal, liquid, and ideal gas state as discussed by the authors. But the tables do not cover the properties of compounds.
Abstract: The thermodynamic tabulations previously published in NSRDS‐NBS‐37 and the 1974 supplement (J. Phys. Chem. Ref. Data 3, 311 [1974]) are extended by 158 new and revised tables. The JANAF Thermochemical Tables cover the thermodynamic properties over a wide temperature range with single phase tables for the crystal, liquid, and ideal gas state. The properties given are heat capacity, entropy, Gibbs energy function, enthalpy, enthalpy of formation, Gibbs energy of formation, and the logarithm of the equilibrium constant for formation of each compound from the elements in their standard reference states. Each tabulation lists all pertinent input data and contains a critical evaluation of the literature upon which these values are based. Literature references are given.

464 citations


Journal ArticleDOI
TL;DR: In this article, the energy levels of the iron atom in all of its stages of ionization, as derived from the analyses of atomic spectra, have been compiled and the percentages for the two leading components of the calculated eigenvectors of the levels are given where available.
Abstract: The energy levels of the iron atom in all of its stages of ionization, as derived from the analyses of atomic spectra, have been compiled. In cases where only line classifications are given in the literature, level values have been derived. The percentages for the two leading components of the calculated eigenvectors of the levels are given where available. Ionization energies are also given.

175 citations


Journal ArticleDOI
TL;DR: In this paper, the transition probabilities for about 1500 allowed spectral lines of the elements scandium and titanium through all stages of ionization have been evaluated and compiled, and the main justifications for the choice of the adopted data and for the accuracy rating are discussed.
Abstract: Atomic transition probabilities for about 1500 allowed spectral lines of the elements scandium and titanium through all stages of ionization have been critically evaluated and compiled. All available literature sources have been utilized. The data are presented in separable tables for each element and stage of ionization and are arranged according to multiplets and, when appropriate, also to transition arrays and increasing quantum numbers. For each line the transition probability for spontaneous emission, the absorption oscillator strength, and the line strength are given along with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels (when available) of the upper and lower atomic states. In addition the estimated accuracy and the literature reference is indicated. In short introduction, which precede the tables for each spectrum, the main justifications for the choice of the adopted data and for the accuracy rating are discussed. A general introduction contains s...

127 citations


Journal ArticleDOI
TL;DR: In this article, structural parameters, vibrational fundamentals, and potential energy functions for internal rotation of n-butane and isobutane were evaluated by the direct sum of terms containing energy levels which were calculated with a one-dimensional potential model.
Abstract: Reported Values of Structural parameters, vibrational fundamentals, and potential energy functions for internal rotation of n‐butane and isobutane are reviewed. The selected values were used to calculate the thermodynamic properties (C°p, S°, (H°‐H°0)/T) in the temperature range of O to model. Contributions of internal rotation were evaluated by the direct sum of terms containing energy levels which were calculated with a one‐dimensional potential model. For internal rotation about the central C‐C bond in n‐butane, energy levels were approximated by two procedures. A inique potential function was assumed for each methyl rotor of n‐butane or of isobutane. Top‐top interactions in isobutane were approximated by the potential parameter V‐d6 which was determined empirically by comparison with thermodynamic data. The calculated and observed values of heat capacities and entropies agree well within experimental uncertainties. Standard enthalpies of formation of 298.15 K for the ideal gaseous state were selected from measured values of heats of combustion and third‐law enthalpies for isomerization. Corresponding values of ΔHf°, and log Kf are tabulated over the same temperature range.

61 citations


Journal ArticleDOI
TL;DR: In this paper, the available molecular parameters, fundamental frequencies, and enthalpy of formation for eight bromo-and indomethanes have been critically evaluated and recommended values selected.
Abstract: The available molecular parameters, fundamental frequencies, and enthalpy of formation for eight bromo‐ and indomethanes have been critically evaluated and recommended values selected. This information has been utilized to calculate the ideal gas thermodynamic properties. C°p, S°, H°−H°0, (G°−H°0)/T, ΔHF°, ΔGF°, and log KF from 0 to 1500 K using the rigid rotor‐harmonic oscillator approximation.

53 citations


Journal ArticleDOI
TL;DR: A survey, comparison, and critical analysis is presented of data compiled from the scientific literature concerning diffusion in copper alloy systems involving elements in Groups IA, IIA, IIIB, IVB, VB, VI, VIB, and VIIB as mentioned in this paper.
Abstract: A survey, comparison, and critical analysis is presented of data compiled from the scientific literature concerning diffusion in copper alloy systems involving elements in Groups IA, IIA, IIIB, IVB, VB, VIB, and VIIB. Here the term ’’copper alloy system’’ is interpreted in the broadest sense. For example, the review of diffusion in the Cu‐M system reports all diffusion situations which involve both copper and element M, including diffusion of Cu in M or in any binary, ternary or multicomponent alloy containing M; diffusion of M in Cu or in any alloy containing Cu; and diffusion of any element in any alloy containing both Cu and M. Topics include volume diffusion, surface diffusion, grain boundary diffusion, tracer diffusion, alloy interdiffusion, electromigration, thermomigration, dislocation‐pipe diffusion, and diffusion in molten metals. An extensive biblography is presented along with figures, tabular presentation of data and discussion of results.

48 citations


Journal ArticleDOI
TL;DR: The ideal gas thermodynamic properties for ethylene and propylene in the temperature range 0 to 1500 K and at 1 atm have been calculated by the statistical thermodynamic method employing the most recent fundamental and molecular spectroscopic constants.
Abstract: The ideal gas thermodynamic properties [H °−H °0, (G°−H °0)/T, (H °−H °0)/T, S °, C °p, ΔHf °, ΔGf °, and log Kf] for ethylene and propylene in the temperature range 0 to 1500 K and at 1 atm have been calculated by the statistical thermodynamic method employing the most recent fundamental and molecular spectroscopic constants. The internal rational contributions to thermodynamic properties for propylene were generated based on an internal rotation partition function formed by summation of internal rotation energy levels. The energy levels were derived from the potential function V (cm−1) =349.2(1−cos 3ϑ)−6.5(1−cos 6ϑ). The calculated heat capacities and entropies were compared with the available experimental values.

44 citations