Line Profile of Charge Density

[Jassel Majevadia]

Quick question. When the line profile is generated from the volumetric data, what are the units of the charge density? Is it still in units of a0^{-3} ?

[Philip Howie]

Hi Jassel,

That depends entirely on the volumetric data!  You'll have to look at the program that generated the data and see what units it uses it its output.

Hope that helps,

Philip

[Jassel Majevadia]

Hi Philip,

Thanks very much for a quick response. The volumetric data I got was from a chgcar file from vasp. Most of the other plots are in inverse cubic bohrs so I am assuming it is the same for this. 

Jazz

[Philip Howie]

Hi Jazz,

Specifically regarding the CHGCAR file from VASP, I found the following:

"The values in the CHGCAR are written in terms of the charge density rho(r) (given in electrons/angstroms^3) multiplied by the volume of your supercell V (given in angstroms^3). In order to confirm this you can look at the integral of rho(r) over the supercell, i.e. "I = int rho(r) dV" which should be equal to the number of electrons N."

Then, from the VESTA manual:

"When these files are read in to visualize isosurfaces and sections, data values are divided by V in the unit of bohr^3. The unit of charge densities input by VESTA is, therefore, bohr^-3."

Therefore, I think you're right, and your line plot will have units of bohr^-3.

Philip