Abstract
The peculiar bonding situation in boron is characterized on the basis of an experimental electron-density distribution which is obtained by multipole refinement against low-temperature single-crystal x-ray diffraction data. A topological analysis of the electron-density distribution reveals one-electron–two-center bonds connecting neighboring icosahedral clusters. A unique polar-covalent two-electron–three-center bond between a pair of atoms of an icosahedral cluster and one atom of the interstitial dumbbell explains the observed charge separation in this high-pressure high-temperature polymorph of boron.
- Received 29 November 2010
DOI:https://doi.org/10.1103/PhysRevLett.106.215502
© 2011 American Physical Society