Search

Your search keyword '"Cacheiro, J.L."' showing total 4 results
Start Over Author "Cacheiro, J.L."
4 results on '"Cacheiro, J.L."'

2. Theoretical gas and dielectric second virial coefficients of CO-Ar

Author

Cacheiro, J.L., Fernandez, B., Rizzo, A., Jansík, B., and Pedersen, T. B.

Abstract

Using coupled cluster singles and doubles linear response theory and the d-aug-cc-pVTZ basis set extended with a 3s3p2d1f1g set of midbond functions, the interaction induced electric dipole polarisability surface of the CO–Ar van der Waals complex is computed. Combining this surface with accurate intermolecular potential energy and electric dipole surfaces, the pressure and dielectric second virial coefficients of the complex are calculated by a classical statistical approach. Excellent agreement with experimental results (to within the experimental error bars) is obtained for the pressure second virial coefficient over a range of temperatures. No previous experimental or theoretical investigations have been carried out for the dielectric second virial coefficient, B_epsilon(T), which is estimated to be about 1.9 cm^6 mol-1 at room temperature. This value results from a balance of terms due to the interaction induced electric dipole polarisability (predominant at high temperatures) and orientational electric dipole contributions.

Published
2008

4. Argon broadening of the 13CO <f>R(0)</f> and <f>R(7)</f> transitions in the fundamental band at temperatures between 80 and 297 K: comparison between experiment and theory

Author

Mantz, A.W., Thibault, F., Cacheiro, J.L., Fernandez, B., Pedersen, T.B., Koch, H., Valentin, A., Claveau, C., Henry, A., and Hurtmans, D.

Subjects
*DIODES, *LEAST squares, *LASER spectroscopy, *POTENTIAL energy surfaces
Abstract

We present measurements of Ar-broadening parameters for the R(0) and R(7) lines in the fundamental band of 13CO at eight temperatures from 80 to 297 K. The broadening parameters are determined by simultaneous least-squares fitting of spectra recorded using a frequency stabilized diode laser spectrometer. The comparison of the broadening parameter values for R(7) derived at room temperature and different pressures from different line profiles shows that an empirical line profile, which takes into account narrowing effects (Dicke narrowing and absorber speed dependence) but neglects any correlation between collisions, is able to describe the observed lines with constant values of the narrowing and broadening parameters over a 10–500 Torr pressure range. Starting from a recent ab initio potential energy surface, theoretical thermally averaged close coupling values of the Ar broadening parameter are calculated for the same temperatures. The comparison between experimental and calculated values shows an overall agreement of 1.5%. [Copyright &y& Elsevier]

Published
2003
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results