Comment on "Observation of the Wigner-Huntington transition to metallic hydrogen"

Understand

Dias and Silvera (Letters, p.

• 715, 2017) claim the observation of the Wigner-Huntington transition to metallic hydrogen at 495 GPa.
• We show that neither the claims of the record pressure or the phase transition to a metallic state are supported by any data and contradict the authors' own unconfirmed previous results.