Penta- and hexa-coordinated beryllium and phosphorus in high-pressure modifications of CaBe<sub>2</sub>P<sub>2</sub>O<sub>8</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31243286.
- Also identified by DOI 10.1038/s41467-019-10589-z and PMC identifier 6594954.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Beryllium oxides have been extensively studied due to their unique chemical properties and important technological applications. Typically, in inorganic compounds beryllium is tetrahedrally coordinated by oxygen atoms. Herein based on results of in situ single crystal X-ray diffraction studies and ab initio calculations we report on the high-pressure behavior of CaBe<sub>2</sub>P<sub>2</sub>O<sub>8</sub>, to the best of our knowledge the first compound showing a step-wise transition of Be coordination from tetrahedral (4) to octahedral (6) through trigonal bipyramidal (5). It is remarkable that the same transformation route is observed for phosphorus. Our theoretical analysis suggests that the sequence of structural transitions of CaBe<sub>2</sub>P<sub>2</sub>O<sub>8</sub> is associated with the electronic transformation from predominantly molecular orbitals at low pressure to the state with overlapping electronic clouds of anions orbitals.