Silicon Allotropy and Chemistry at Extreme Conditions

An extensive theoretical survey of low-density allotropy in silicon.

Using a variety of computational approaches, we demonstrate that the energy landscape of low-density silicon (e.g. silicon clathrates) is considerably more complicated than suggested by previous studies and identify several new prospective low-energy silicon allotropes. Many of our new prospective silicon allotropes contain 4-membered rings, previously thought to be incompatible with low-energy...

Forcing Cesium into Higher Oxidation States via Useful Hard X-ray Induced Chemistry at Extreme Conditions

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The Extreme Conditions Beamline P02.2 and the Extreme Conditions Science Infrastructure at PETRA III

A detailed description is presented of the Extreme Conditions Beamline P02.2 for micro X-ray diffraction studies of matter at simultaneous high pressure and high/low temperatures at PETRA III, in Hamburg, Germany. This includes performance of the X-ray optics and instrumental resolution as well as an overview of the different sample environments available for high-pressure studies in the diamon...

Titanium Alloys at Extreme Pressure Conditions

The electronic structures of the early transition metals are characterised by the relationship that exists between the occupied narrow d bands and the broad sp bands. Under pressure, the sp bands rise faster in energy, causing electrons to be transferred to the d bands (Gupta et al., 2008). This process is known as the s-d transition and it governs the structural properties of the transition me...

Structure, Bonding, and Mineralogy of Carbon at Extreme Conditions