Theory of bonding charge density in [beta] NiAl
- National Renewable Energy Lab., Golden, CO 80401 (United States)
Fox and Tabbernor have recently measured the four lowest structure factors F(G) of NiAl using highly accurate high energy electron diffraction. In this paper, the authors present a systematic comparison of their results with ab initio band theory, in the context of the local density formalism. The authors find very good agreement for the three of the four lowest measured structure factors, while our F(200) is [approximately]0.4 e/cell higher. The authors tentatively attribute this difference to uncertainties in the treatment of the temperature factors in non-monoatomic compounds. Indeed, comparing with experiment our calculation for the monoatomic Si crystal (where the temperature term factors out), the authors find that theory reproduces the measured structure factors to within a very small deviations of [approximately]0.02 e/atom. The authors have also examined the effect of high Fourier components that are not currently amenable to measurements on the ensuring NiAl deformation electron density distribution (DEDD) maps. The authors find that the truncation of the Fourier series after four structure factors misses the directional d-like charge lobes near the Ni sites.
- OSTI ID:
- 6987384
- Journal Information:
- Acta Metallurgica; (United States), Vol. 40:9; ISSN 0001-6160
- Country of Publication:
- United States
- Language:
- English
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