Z. W. Lu

Theory of bonding charge density in β′ NiAl

Abstract Fox and Tabbernor [Acta metall. mater.39, 669 (1991)] have recently measured the four lowest structure factors F(G) of NiAl using highly accurate high energy electron diffraction. We present here a systematic comparison of their results with ab initio band theory, in the context of the local density formalism. We find very good agreement for the three of the four lowest measured structure factors, while our F(200) is ∼0.4 e/cell higher. We 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), we find that theory reproduces the measured structure factors to within a very small deviations of ∼0.02 e/atom. We have also examined the effect of high Fourier components that are not currently amenable to measurements on the ensuing NiAl deformation electron density distribution (DEDD) maps. We find that the truncation of the Fourier series after four structure factors misses the directional d-like charge lobes near the Ni sites. We show that static and dynamic DEDD give a similar picture of the bonding.

SPIN-POLARIZATION-INDUCED STRUCTURAL SELECTIVITY IN PD3X AND PT3X (X=3D) COMPOUNDS

Spin polarization is known to lead to important magnetic and optical effects in open-shell atoms and elemental solids, but has rarely been implicated in controlling structural selectivity in compounds and alloys. Here we show that spin-polarized electronic structure calculations are crucial for predicting the correct

Relativity-Induced Ordering and Phase Separation in Intermetallic Compounds

T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0

Comparison of experimental and theoretical electronic charge distribution in γ-TiAl

crystal structures for

The electronic charge distribution in crystalline silicon: comparison of ab initio theory and experiment

{\mathrm{Pd}}_{3}X

Ground state structures of intermetallic compounds: A first-principles Ising model

and

Zinc-blende-wurtzite polytypism in semiconductors

{\mathrm{Pt}}_{3}X

First-principles statistical mechanics of structural stability of intermetallic compounds

compounds. Spin polarization leads to (i) stabilization of the

Electronic charge distribution in crystalline diamond, silicon, and germanium.

{L1}_{2}

Predictions and systematizations of the zinc-blende--wurtzite structural energies in binary octet compounds

structure over the