Computer Model Shows Tricalcium Silicate (IMAGE) Rice University Caption A computer model shows tricalcium silicate with a defect known as a screw dislocation, which influences the brittle properties of the crystal structure. The atoms on the periphery are faded because they are little affected by the dislocation core at the center of the disc. Credit Lei Tao/Rice University Usage Restrictions For news reporting purposes only. 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.