Quantitative convergent-beam electron diffraction and quantum crystallography—the metallic bond in aluminium

摘要: The technique of quantitative convergent-beam electron diffraction (QCBED) is reviewed as a method for making very accurate and precise measurements low-order bonding-sensitive structure factors. As such, it with the potential to make significant contributions field quantum crystallography. To demonstrate this, application QCBED in determining nature metallic bond aluminium examined detail. importance precision factor measurement when comes bonding distributions, especially metals, becomes obvious from this examination. Uncertainties low ±0.1% are routinely attainable by shown be important reliably locating charge. In case aluminium, nearly free gas metal where distribution subtler than most other materials, bonds entirely tetrahedrally centred. This conclusion that could not have been reached experimentally without levels offered QCBED.