Crystal Structures Of Carbon And Hydrogen (image) Helmholtz-Zentrum Dresden-Rossendorf Share Print E-Mail Caption Even under extremely high pressure, such as those in the interior of Neptune or Uranus, there are stable crystal structures of carbon (orange) and hydrogen (gray). This discovery by HZDR researchers reveals new possibilities for the inner structure of the ice giants. Credit HZDR / J. Vorberger Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.