[gmx-users] Calculating the center of mass of a molecule

[Andrew DeYoung]

Hi,

I am afraid that this is a silly, easy question.  But, when I search around,
I cannot seem to find the answer.  I am sorry to bother you.

My question is, is there a Gromacs utility to calculate the center of mass
of a molecule?  For example, I would like to see how the x, y, and z
positions of the center of mass of a particular molecule vary over time.
g_dist computes the distance and distance vector between the center of
masses of 2 groups, but I would like the centers of masses themselves, not
the vector between them.

Thank you kindly.

Andrew DeYoung
Carnegie Mellon University