CaltechAUTHORS
  A Caltech Library Service

Photoabsorption in carbon monoxide: Stieltjes–Tchebycheff calculations in the separated-channel static-exchange approximation

Padial, N. and Csanak, G. and McKoy, B. V. and Langhoff, P. W. (1978) Photoabsorption in carbon monoxide: Stieltjes–Tchebycheff calculations in the separated-channel static-exchange approximation. Journal of Chemical Physics, 69 (7). pp. 2992-3004. ISSN 0021-9606. http://resolver.caltech.edu/CaltechAUTHORS:PADjcp78

[img]
Preview
PDF - Published Version
See Usage Policy.

1178Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:PADjcp78

Abstract

Theoretical investigations of total and partial-channel photoabsorption cross sections in carbon monoxide are reported employing the Stieltjes–Tchebycheff (S–T) technique and separated-channel static-exchange calculations. Pseudospectra of discrete transition frequencies and oscillator strengths appropriate for individual excitations of each of the six occupied molecular orbitals are constructed using Hartree–Fock core functions and normalizable Gaussian orbitals to describe the photoexcited and ejected electrons. Use of relatively large basis sets of compact and diffuse functions insures the presence of appropriate discrete Rydberg states in the calculations and provides sufficiently dense pseudospectra for the determination of convergent photoionization cross sections from the S–T technique. The calculated discrete vertical electronic excitation spectra are in very good agreement with measured band positions and intensities, and the partial-channel photoionization cross sections are in correspondingly good accord with recent electron–electron (e,2e) coincidence, synchrotron-radiation, and line-source branching-ratio measurements. Predicted resonance features in the X, B, O2s−1, and carbon K-shell channels are in particularly good agreement with the positions and intensities in the measured cross sections. A modest discrepancy between experiment and theory in the A-channel cross section is tentatively attributed to channel-coupling mechanisms associated with opening of the 1pi shell. The total vertical electronic S–T photoionization cross section for parent-ion production is in excellent agreement with recent electron–ion coincidence measurements. Comparisons are made between ionization processes in carbon monoxide and in the previously studied nitrogen molecule, and similarities and differences in the respective cross sections are clarified in terms of conventional molecular-orbital theory.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1063/1.437017DOIUNSPECIFIED
http://link.aip.org/link/?JCPSA6/69/2992/1PublisherUNSPECIFIED
Additional Information:Copyright © 1978 American Institute of Physics. Received 13 March 1978. The authors gratefully acknowledge the financial support of the US-Latin American Science Program, NSF(OIP)-CNPq (Brazil), of the FAPESP (Sao Paulo, Brazil), of the BID, and of the Donors of the Petroleum Research Fund, administered by the American Chemical Society. They also thank Professor Sergio Porto for his support of the cooperative project, Professor J.E. Ripper for making BID support available, Professor Nelson Machado for efficient operation of the Computing Center, Universidade Estadual de Campinas, where the calculations were performed, and Guillermo Barrera, Dante Ming Valent, and Marisa de Souza for computational assistance. Supported in part by the U.S.-Latin American Cooperative Science Program, NSF(OIP)-CNPq (Brazil), and by the Donors of the Petroleum Research Fund, administered by the American Chemical Society.
Funders:
Funding AgencyGrant Number
U.S.-Latin American Sciences ProgramUNSPECIFIED
Petroleum Research FundUNSPECIFIED
Record Number:CaltechAUTHORS:PADjcp78
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:PADjcp78
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11414
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:13 Aug 2008 20:43
Last Modified:26 Dec 2012 10:13

Repository Staff Only: item control page