Ab initio quantum mechanical characterization of the low-lying cation doublet states of uracil. Interpretation of UV and x-ray photoelectron spectra

.. uracil/sup +/. transitions of the uv photoelectron spectrum is A'', A', A'', A', A'' in order from lowest to higher ionization potentials. The molecular fragment basis set gives the experimental ordering with the Koopmans' theorem approximation but gives an incorrect ordering (A', A'', A' approx. A'', A') when configuration interaction is applied. The double zeta basis set, on the other hand, gives an incorrect ordering with the Koopmans' theorem approximation (A'', A'', A', A', A'') but gives the experimental ordering after configuration interaction is applied. The best of these calculations utilized the double zeta basis set plus configuration interaction; these results lend support to the previously made assignment of the first five bands of the uv photoelectron spectrum. The results of the double zeta calculation have been used to extend the assignment of the uv photoelectron spectrum to A'', A', A'', A', A'', A'', A',more » A'. The eight inner-shell molecular orbitals and their orbital energies from the double zeta calculation have been used to assign the experimental x-ray photoelectron spectrum of uracil. The following ordering was computed: O/sub 1/ (bonded to C/sub 2/), O/sub 2/ (bonded to C/sub 4/), N/sub 1/, N/sub 3/, C/sub 2/, C/sub 4/, C/sub 6/, C/sub 5/ in order of decreasing ionization potential.« less -->
ISSN: 1541-5740
0022-3654
DOI: 10.1021/j100452a021
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_________::dc1ed06a5f0cd67b9309af13e116ad25
https://doi.org/10.1021/j100452a021
Přírůstkové číslo: edsair.doi...........dc1ed06a5f0cd67b9309af13e116ad25
Autor: James D. Petke, Pierre R. LeBreton, T. J. O'Donnell, Lester L. Shipman
Rok vydání: 1980
Předmět:
Zdroj: The Journal of Physical Chemistry. 84:1975-1982
ISSN: 1541-5740
0022-3654
DOI: 10.1021/j100452a021
Popis: AB initio configuration interaction wave functions have been computed for the ground singlet state and the 10 lowest A' and A'' cation doublet states of uracil. Both the small molecular fragment basis set and a much larger double zeta basis set have been employed. The experimental ordering of the terminus states in the uracil ..-->.. uracil/sup +/. transitions of the uv photoelectron spectrum is A'', A', A'', A', A'' in order from lowest to higher ionization potentials. The molecular fragment basis set gives the experimental ordering with the Koopmans' theorem approximation but gives an incorrect ordering (A', A'', A' approx. A'', A') when configuration interaction is applied. The double zeta basis set, on the other hand, gives an incorrect ordering with the Koopmans' theorem approximation (A'', A'', A', A', A'') but gives the experimental ordering after configuration interaction is applied. The best of these calculations utilized the double zeta basis set plus configuration interaction; these results lend support to the previously made assignment of the first five bands of the uv photoelectron spectrum. The results of the double zeta calculation have been used to extend the assignment of the uv photoelectron spectrum to A'', A', A'', A', A'', A'', A',more » A'. The eight inner-shell molecular orbitals and their orbital energies from the double zeta calculation have been used to assign the experimental x-ray photoelectron spectrum of uracil. The following ordering was computed: O/sub 1/ (bonded to C/sub 2/), O/sub 2/ (bonded to C/sub 4/), N/sub 1/, N/sub 3/, C/sub 2/, C/sub 4/, C/sub 6/, C/sub 5/ in order of decreasing ionization potential.« less
Databáze: OpenAIRE
Externí odkaz: