Electron Density, Electrostatic Potential, Electron Localization Function(ELF)

CPMD can compute several ``gridded'' properties of the whole system like the total electron density (RHOOUT) or the ELECTROSTATIC POTENTIAL or the electron localization function (ELF, not to be confused with electron localization through Wannier centers and orbitals). The aforementioned keywords can be added to the wavefunction optimization run or one can just RESTART from a previously computed wavefunction.

The resulting files are unformatted binary data and need to be converted into a format that can be handled by visualization programs or further analysis tools. This can be done with the cpmd2cube.x utility (see section 10.2 for a full description of all options). For visualization purposes usually a rather coarse grid is sufficient, so we use, e.g.: cpmd2cube.x -halfmesh -rho DENSITY to generate a DENSITY.cube file; similar for ELPOT and ELF for the electrostatic potential and electron localization function, respectively.