On Sun, Jan 15, 2023, Dulal Mondal via AMBER wrote:
>
>I have a trajectory file (nc file) which contains only position information
>but no velocity information.
>1) How can I calculate the center of mass (COM) of a particular residue
>(HIS-64)?
In cpptraj, two linked statements should do the trick:
vector his64com center :64 # computes the center of mass of residue 64
run
writedata his64.crd vectraj his64com trajfmt crd noorigin
#writes out the center of mass coordinates for residue 64 at each
# frame of the trajectory to the file his64.crd
>2) How can I calculate momentum?
Without having velocities, you can't get at momenta.
...good luck...dac
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Received on Mon Jan 16 2023 - 11:00:02 PST