(IMAGE) Yokohama National University Caption The HS-I, CS-I, and CS-II structures of hydrate correspond to the Z, A15, and C15 phases of the Frank-Kasper phase, respectively. With the discovery of HS-I, the primitive structures at the three vertices are all in place. Derivative structures arise from cage deformation. Polyhedron: green, 14-hedron; red, 15-hedron. Plot: gray, mixed phases found in alloys. Credit Yokohama National University Usage Restrictions News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only. License Original 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.