Valence-electron density in silicon and InSb under high pressure by X-ray diffraction

The effects of high pressure on the valence-electron density in silicon and indium antimonide are investigated by x-ray diffraction. It is found that near the transition to the metallic -tin structure the scattering from the valence electrons sharply decreases, indicating either smearing of the bonding charges or increased anharmonicity in the thermal vibrations.