COF and Modified COF (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption At left is the simulated 3D molecular structure of a covalent organic framework, and at right is a modified framework. The yellow spheres in the structure on the left indicate a pore diameter of 2.9 nanometers, and the cyan spheres in the structure on the right indicate a pore diameter of 2.6 nanometers. Credit Berkeley Lab 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.