ELF and c2x

Many DFT codes can calculate the electron localisation function. Note that pseudopotential codes omit the core electrons, and thus will produce an ELF which can differ significantly from that resulting from an all-electron calculation.

C2x gained support for reading .elf and .elf_fmt output from Castep in c2x 2.35. The example below demonstrates the use of this.

And in c2x 2.42c it gained the ability to read Abinit's _ELF and VASP's ELFCAR files directly. Given that an _ELF is similar to a _DEN file, and an ELFCAR file is similar to a CHGCAR file, with earlier versions of c2x one can rename the file, and run c2x with ‑cR to read a "charge density" and not rescale it.

Siesta does not offer ELF output. QE does, but it doesn't agree with the other codes, which does not mean that it is completely wrong, as there are many ELFs.

With Castep prior to version 25.1 one has to be a little careful with grid scales to prevent FFT aliasing artifacts.

For further details on ELFs, see