Unit chg2cube's output

Vasp transition state theory tools

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Unit chg2cube's output

Post by s.zarrini »

Dear all,

As I know the unit in CHGCAR is \frac{electron/A^3} or maybe \frac{electron/Bohr^3} as the electron density, also, the unit in CUBE file could probably be the Electron. So, neither of them has something with energy, I mean eV or Hartree, then I was wondering why the 1=BOHR/HARTREE or 2=ANGSTROMS/eV would be the unit of the output in chg2cube.pl? I was expecting to have some something like the electron or, at least, \frac{electron/A^3} or \frac{electron/Bohr^3} not eV or HARTREE in the content.

I need the difference charge density of my system contains 3 species in CUBE, to do so, I did like this:

chg2cube.pl (chgdiff.pl (CHGCAR1, chgsum.pl (CHGCAR2, CHGCAR3)) = CHGCAR.cube

So, would you please let me know what the unit of my output is?

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Re: Unit chg2cube's output

Post by graeme »

For charge density, I agree that it is only Bohr vs Ang matters. We have, however, also used this script for the local electrostatic potential, for which the energy unit is included.

But anyway, for your conversion, it should convert between a total charge per voxel (in the CHGCAR format) to an electron density per Bohr (in the cube format).
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