Hi Qian,
The e3 just means exponent, in other words, multiply by 10**3 (thousands). It is not the units. The units are based on whatever length scale the data are in, usually angstroms, so the volume would be cubic angstroms and the area square angstroms.
I hope this helps,
Elaine
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Elaine C. Meng, Ph.D.
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco
> On Sep 8, 2017, at 1:01 AM, Pu Qian <p.qian@sheffield.ac.uk> wrote:
>
> Dear Chimera developers,
> I'm using Chimera to estimate molecular weight from cryo-em map through volume viewer/tools/measure volume and area/
> The value of the volume I got is in e3 unit. What dies this e3 mean. This e3 unit is used for area as well, which confused me.
> The version I'm using is 1.12.
> It seems that the e3 equals nm3, but I'm not sure. It would be a great appreciated if you could help me to make it clear. Thanks
> Best regards
> Qian