Structure of the Iridium Oxide Crystal (Ba3CeIr2O9) (image) University of Cologne Share Print E-Mail Caption The two adjacent iridium atoms (dimer) are shown in green. The elements oxygen (O, red), barium (Ba, grey) and cerium (Ce, turquoise) are also involved in the crystal structure. Credit Markus Grueninger, University of Cologne 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.