Figure 2 (IMAGE) RIKEN Caption Figure 2: Addition of hydrogen to a metal hydride cluster with retention of the single crystal morphology. Top: A schematic representation of the hydrogen addition reaction. Middle: Photographs of the crystal at different reaction times. The crystal color changed from black to red as the reaction proceeded. Bottom: Differential electron density maps showing the appearance and electron density increase of the two new hydride ligands (blue) as the hydrogenation reaction proceeded. Credit RIKEN Usage Restrictions None License Licensed content 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.