Experimental and calculated momentum densities for the valence orbitals of carbon tetrafluoride
1984; Elsevier BV; Volume: 91; Issue: 1 Linguagem: Inglês
10.1016/0301-0104(84)80041-5
ISSN1873-4421
Autores Tópico(s)Inorganic Fluorides and Related Compounds
ResumoCarbon tetraflouoride has been investigated by binary (e,2e) spectroscopy at 1200 eV impact energy. Binding energy spectra (10–60 eV) at azimuthal angles of 0° and 8° are reported and are found to be in quantitative agreement with a previous Green's function calculated spectrum. Momentum distributions corresponding to individual orbitals are also reported and compared with theoretical momentum distributions evaluated using double-zeta quality SCF wavefunctions. Excellent agreement between experimental and theories is found for the strongly bonding 3t2 orbital and the antibonding 4a1 orbital but agreement is less good for the outermost non-bonding orbitals. Intense structure due to molecular density (bond) oscillation is observed experimentally in the region above 1.0 ao−1 in the case of the non-bonding 4t2 orbital. It is also notable that the measured 4a1 momentum distribution exhibits an extremely well-defined “p” character with clear separation between the s and p components. Contour maps of the position-space and momentum-space orbital densities in the F-C-F plane of the molecule are used to provide a qualitative interpretation of the features observed in the momentum distribution. In order to further extend momentum-space chemical concepts to three-dimensional systems, constant density surface plots are also used to give a more comprehensive view of the density functions of the CF8 molecule.
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