Hi All,
2012/8/23 Daniel Roe <daniel.r.roe.gmail.com>:
> Hi,
>
> >
> More specifically, in the "<file>_a.xmgr" file the second column is
> the average distance travelled by all the atoms, i.e. sqrt(
> SUM[dist^2]/N ), where N is the number of atoms. Columns 3 and 4 in
Actually, you are not right. sqrt(SUM[dist^2]/N )>=SUM[dist]/N, and a
case of equality appears when 'dist'=const.
In general form, for large numbers, mean square = square of mean + variance
2Bala:
If you use 'average' key word, you will get only 2 columns, one for
time and one for the appropriate mean value.
_r - mean square displacement,
_a - mean displacement,
_x, _y, _z - Cartesian decomposition.
> this case are the distance travelled by each individual atom, i.e.
> sqrt( dist^2 ), so col2 should not be equal to the straight average of
> cols 3 and 4, but rather col2 = sqrt( (col3^2 + col4^2) / 2), which
> you can verify it is.
>
> Hope this helped.
>
> -Dan
>
> --
--
Sincerely,
Dmitry Mukha
Institute of Bioorganic Chemistry, NAS, Minsk, Belarus
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Received on Sat Aug 25 2012 - 09:00:02 PDT
