Journal ArticleDOI
Determination of Mean Molecular Polarizabilities and Second Virial Coefficients of Gases by Scanning-Wavelength Interferometry
TLDR
In this paper, the dispersion of the second virial coefficients B(T) was determined in the case of neopentane at four different temperatures between 283 and 363 K. Berthelot's equation gave the best overall-fit of reasonable experimental ß(r)-values of NEOPENTANE in the extended range 283 < 7" < 550.Abstract:
Scanning-wavelength interferometry is proposed as a method for precise investigations of the (complex) index of refraction of gases in dependence on wavelength A, temperature and pressure p. At — 293 the (real) index of refraction of the gases He, Ne, Ar, H2, N2, 02 and CH4 has been investigated in dependence on (0 < < 1.4 bar) and (400 nm < < 700 nm) in order to determine the dispersion of the mean molecular polarizabilities a(i). In the case of neopentane C(CH3)4 corresponding measurements are accomplished at four different temperatures between 283 and 363 K. In addition to the hitherto unknown dispersion of ( ) second virial coefficients B(T) are determined. Berthelot's equation gave the best overall-fit of reasonable experimental ß(r)-values of neopentane in the extended range 283 < 7" < 550 . For this gas the influence of temperature on a(A) and the influence of gas Sorption on B(T)measurements are discussed.read more
Citations
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Journal ArticleDOI
Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen
TL;DR: In this paper, new fundamental equations of state for parahydrogen, normal hydrogen, and orthohydrogen were developed to replace the existing property models, and the uncertainties of vapor pressures and saturated liquid densities vary from 0.1% to 0.2%.
Journal ArticleDOI
Rayleigh scattering by air
TL;DR: In this paper, the Rayleigh scattering cross section for air is calculated from published experimental and theoretical results account being taken of the dispersion of the King correction factor, and the spectral region 0.2 mμ ⩽ λ ⌽ 1.0 mμ is covered.
Journal ArticleDOI
Diffusion-limited reactions in dynamic heterogeneous media
TL;DR: A general mathematical framework is proposed to compute the distribution of first-passage times in a dynamically heterogeneous medium and shows how the dynamic disorder broadens the distribution and increases the likelihood of both short and long trajectories to reactive targets.
Journal ArticleDOI
Interferometric measurements of the dipole polarizability α of molecules between 300 K and 1100 K
Uwe Hohm,Klaus Kerl +1 more
TL;DR: The temperature dependence of the dipole polarizability α(λ, T) of free atoms and molecules was determined by precise measurements of the refractive index n of gases in the extended temperature range between 300 K and 1100 K for wavelength λ = 632·99 nm, using a specially constructed Michelson twin interferometer as mentioned in this paper.
Journal ArticleDOI
Correlated van der Waals coefficients for dimers consisting of He, Ne, H2, and N2
W. Rijks,P. E. S. Wormer +1 more
TL;DR: In this article, the time-dependent coupled Hartree-Fock frequency-dependent polarizabilities have been corrected for true correlation effects by means of manybody perturbation theory, and the van der Waals coefficients of all possible dimers have been obtained by the use of the Casimir-Polder relation.
References
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Book
Molecular Quantum Mechanics
Peter Atkins,Ronald S. Friedman +1 more
TL;DR: In this paper, the Schrodinger equation has been used to describe the properties of the Schröter equation for electronic structure calculations and its application in the field of molecular mechanics.