Fig. 8: DFT calculations of DOS and charge density difference of Py-TFIm-25 COF.
From: Efficient and selective capture of thorium ions by a covalent organic framework

a–f DOS of various metal cations adsorption on Py-TFIm-25 COF. The inset shows the calculated isosurface (level 0.007) of charge density difference upon the adsorption of the mental cations on the N atom of Im.