VMD-L Mailing List

From: Leonardo Trabuco (ltrabuco_at_ks.uiuc.edu)
Date: Tue Nov 03 2009 - 15:13:19 CST

On Tue, Nov 3, 2009 at 3:08 PM, Bernardo Sosa Padilla Araujo
<bernardospa_at_gmail.com> wrote:
> Hi all,
>
> can anyone tell me what the units are for the radius of gyration when using
> the command "measure rgyr". Is it (A*A) or A?
> In other terms, is it the square of Rg or just Rg?

Rg is a radius, thus given in Angstroms. From the VMD source code, the
definition is:
rgyr := sqrt(sum (mass(n) ( r(n) - r(com) )^2)/sum(mass(n)))

Cheers,
Leo

> Thanks a lot,
>
> Bernardo 

-- 
Leonardo Trabuco, Ph.D. candidate
Theoretical and Computational Biophysics Group
University of Illinois at Urbana-Champaign