A STUDY OF ANISOTROPY IN THE MOMENTUM DENSITY OF KHCO3 USING HIGH-RESOLUTION COMPTON-SCATTERING
UNSPECIFIED (1994) A STUDY OF ANISOTROPY IN THE MOMENTUM DENSITY OF KHCO3 USING HIGH-RESOLUTION COMPTON-SCATTERING. JOURNAL OF PHYSICS-CONDENSED MATTER, 6 (42). pp. 8701-8710. ISSN 0953-8984Full text not available from this repository.
We report directional Compton profiles of KHCO3 measured along the pipi direction (parallel to the HCO3 layers and parallel to the H bonds), the pisigma direction (parallel to the layers and orthogonal to the H bonds), and the sigmasigma direction (orthogonal to the layers and orthogonal to the H bonds) using a high-resolution Compton spectrometer at the LURE-DCI synchrotron facility in France operating at 19.9 keV. These measurements confirm the significant anisotropy of the electron distribution in KHCO3, which we associate with the H bonds. This assumption is supported by the fact that the free-atom model (anions HCO3- without H bonds) is not able to describe our experimental results. A molecular orbital-LCAO-self-consistent model has been used to calculate the anisotropies with different size clusters, and taking into account or not the environment of the dimeric anion (HCO3)(2)2- containing conta two H bonds. The calculated anisotropies based on free K2 (HCO3)2 yield the main features of the experimental anisotropies with respect to the pipi direction. More sophisticated calculations involving K4(HCO3)4 and K6(HCO3)6 with the dimeric anion (HCO3)2(2-) surrounded by point charges have not improved the agreement with the experiment. Moreover, none of these calculations is able to describe the small measured anisotropy between pisigma and sigmasigma directions.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||JOURNAL OF PHYSICS-CONDENSED MATTER|
|Publisher:||IOP PUBLISHING LTD|
|Date:||17 October 1994|
|Number of Pages:||10|
|Page Range:||pp. 8701-8710|
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