From: John Stone (johns_at_ks.uiuc.edu)
Date: Tue Jul 24 2012 - 10:26:00 CDT

Hi,
  Yes, the units should be X / A^3, where "X" is the unit resulting
from the combination of the weight field you chose and the atom
radii information in the molecular structure. You can see the code
that computes the density map here: VolMapCreateDensity::compute_frame():
 http://www.ks.uiuc.edu/Research/vmd/doxygen/VolMapCreate_8C-source.html#l00542

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Tue, Jul 24, 2012 at 11:05:43AM +0200, raunest wrote:
> Dear VMD users,
>
> I am using GROMACS for MD Simulations. To analyze the average sodium
> distributions in my trajectory I calculated the mass weighted densities
> via VolMap.
>
> For edge length I choose 1 Angstrom, and saved the result into an OpenDX
> file.
>
> My question is:
> Which unit does these values inside the OpenDX file have ?
>
> maybe u / A^3 ?
>
> Thanks!
> Martin

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