Symmetry-broken crystal structure of elemental boron at low temperature

@article{Widom2008SymmetrybrokenCS,
  title={Symmetry-broken crystal structure of elemental boron at low temperature},
  author={Michael Widom and M. Mihalkovi{\vc}},
  journal={Physical Review B},
  year={2008},
  volume={77},
  pages={064113}
}
The crystal structure of boron is unique among chemical elements, highly complex, and imperfectly known. Experimentalists report the �-rhombohedral (black) form is stable over all temperatures from absolute zero to melting. However, early calcu- lations found its energy to be greater than the energy of the �-rhombohedral (red) form, implyingcannot be stable at low temperatures. Furthermore, � exhibits partially occupied sites, seemingly in conflict with the thermodynamic requirement that… 
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