Journal article
Electron-positron momentum density in TTF-TCNQ
We present measurements of the positron two-dimensional angular correlation of annihilation radiation (2D-ACAR) in TTF-TCNQ. We report also theoretical simulations of the 2D-ACAR in which the electron wave functions were expressed as TTF or TCNQ molecular orbitals obtained from self-consistent quantum chemical calculations.
The positron wave function was calculated taking the charge transfer from TTF to TCNQ as a parameter. The best agreement with the experiment is obtained for a charge transfer of 0.7 electrons from the TTF to the TCNQ molecules. This is larger than the value of 0.55 obtained from a study of the Kohn anomaly.
We investigate also the shape and position of the Fermi surface and conclude that a simple planar Fermi surface is consistent with our measurements.
Language: | English |
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Year: | 1997 |
Pages: | 2048-2055 |
ISSN: | 10953795 , 01631829 , 1550235x , 10980121 and 24699950 |
Types: | Journal article |
DOI: | 10.1103/PhysRevB.55.2048 |