M. S. Ahmed
Feb 1, 1950
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0
Influential Citations
1
Citations
Journal
Nature
Abstract
SINGLE-CRYSTAL rotation photographs of lithium hydride (LiH), using copper Kα radiation, show clearly that the structure is of a sodium chloride type, but that the lithium and hydrogen atoms are by no means completely ionized. Atomic scattering curves have been drawn from the corrected intensity data for the ‘all even’ reflexions (Li + H); and for the ‘all odd’ reflexions (Li−H). From these the separate atomic scattering curves for the Li+x ion and for the H−x ion (uncorrected for temperature scattering) have been deduced. The thermal scattering, which is of the same order as that in sodium chloride (though differently distributed), has also been studied separately by means of ‘diffuse’ Laue photographs. The results show that the most probable state of ionization is Li+0 25, H−0 25. The absolute limits that could be supposed to agree with the observations would be 50 per cent ionic character or, at the opposite extreme, complete covalency.