Comment on "Superhard Semiconducting Optically Transparent High Pressure Phase of Boron"

This Comment points out a number of errors in the recent paper by Zarechnaya, Dubrovinskaia, Dubrovinsky et al. (Phys. Rev. Lett. 102, 185501). It was submitted on 1 June 2009. The Comment was not recommended for publication (decision of 14 August 2009), largely because errors of the Zarechnaya paper can be easily detected by the readers