ST12-germanium (IMAGE) Carnegie Institution for Science Caption This is an illustration of ST12-germanium's complex tetragonal structure with tetrahedral bonding, courtesy of Haidong Zhang. Credit Haidong Zhang Usage Restrictions With credit 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.