Volume 17, Issue 1, January 1988
Index of content:
Pressure and Density Series Equations of State for Steam as Derived from the Haar–Gallagher–Kell Formulation17(1988); http://dx.doi.org/10.1063/1.555819View Description Hide Description
Two equations of state for the properties of steam, which are in the form of power series in pressure and density, are developed from the HGK84 formulation. These equations are of high accuracy in the equilibrium region where extensive measurements exist. They also accurately represent the extrapolated data in the metastable region between the vapor saturation and spinodal lines. The accuracy of the representations as a function of the number of terms of the series is presented. Their greatest utility is their use for high accuracy calculations that involve small to moderate departures from ideal‐gas behavior. Conversion relationships for the second through the tenth coefficients of the pressure and density series, which apply to the corresponding virial coefficients, are presented. The pressure and density expansions are advantageous for efficient numerical calculations of water vapor properties in the equilibrium and metastable regions.
Absolute Cross Sections for Molecular Photoabsorption, Partial Photoionization, and Ionic Photofragmentation Processes17(1988); http://dx.doi.org/10.1063/1.555821View Description Hide Description
A compilation is provided of absolute total photoabsorption and partial‐channel photoionization cross sections for the valence shells of selected molecules, including diatomics (H2, N2, O2, CO, NO) and triatomics (CO2, N2O), simple hydrides (H2O, NH3, CH4), hydrogen halides (HF, HCl, HBr, HI), sulfur compounds (H2S, CS2, OCS, SO2, SF6), and chlorine compounds (Cl2, CCl4). The partial‐channel cross sections presented refer to production of the individual electronic states of molecular ions and also to production of parent and specific fragment ions, as functions of incident photon energy, typically from ∼20 to 100 eV. Total photoabsorption cross sections above the first ionization threshold are reported from conventional optical measurements obtained using line and continuum sources and from ‘‘equivalent‐photon’’ dipole (e,e) electron scattering experiments. Partial photoionization cross sections for production of electronic states of molecular ions are obtained from photoelectron spectroscopy and from dipole (e,2e) coincidence measurements.Photoionization mass spectrometry and dipole (e, e+ion) coincidence studies provide measurements of partial cross sections for ionic photofragmentation (i.e., dissociative photoionization). Photoelectron anisotropy factors, which together with electronic partial cross sections provide cross sections differential in photon energy and in ejection angle, are also reported. There is generally good agreement between cross sections measured by the physically distinct optical and dipole electron‐impact methods. The cross sections and anisotropy factors also compare favorably with selected a b i n i t i o and model potential (X‐alpha) calculations which provide a basis for interpretation of the measurements.
17(1988); http://dx.doi.org/10.1063/1.555818View Description Hide Description
The energy levels of the molybdenum atom, in all stages of ionization for which experimental data are available, have been compiled. Ionization energies, either experimental or theoretical, and experimental g‐factors are given. Leading components of calculated eigenvectors are listed.
Standard Chemical Thermodynamic Properties of Polycyclic Aromatic Hydrocarbons and Their Isomer Groups I. Benzene Series17(1988); http://dx.doi.org/10.1063/1.555823View Description Hide Description
The polycyclic aromatic hydrocarbons can be organized into an infinite number of series in each of which successive isomer groups differ by C4H2. The first series starts with benzene, and chemical thermodynamic tables are presented here for C6H6, C1 0H8, C1 4H1 0, C1 8H1 2, C2 2H1 4, and C2 6H1 6 in the ideal gas phase. Since chemical thermodynamicproperties are known for only several polycyclic aromatic hydrocarbons, the properties of individual species have been estimated using Benson group values of Stein and Fahr for temperatures from 298.15 to 3000 K. Values of C ○ P , S°, Δf H°, and Δf G° have been calculated in joules for a standard state pressure of 1 bar. The chemical thermodynamicproperties of the isomer groups have also been calculated. This provides a basis for extrapolating to higher carbon numbers where it is not feasible to consider individual molecular species.