From: Andrew DeYoung (
Date: Sat May 26 2012 - 12:27:53 CDT

Hi again,

If the Gromacs configuration and trajectory file formats indeed do not
support the inclusion of charge information, and if this will make
monitoring the dipole moment using Dipole Moment Watcher, then I can think
of one potential workaround.

I can use the Gromacs utility g_dipoles to calculate the x, y, and z
components of the dipole moment as a function of time (in addition to the
norm of the dipole moment vector as a function of time) and print this
information to a text file.

So a possible workaround would be to somehow animate a 3-D arrow in VMD so
that I can watch how the dipole moment vector changes as I watch the
trajectory. Is it possible to input a list of vector components and draw
the corresponding vector on the respective frames of the trajectory?

Thank you!

Andrew DeYoung
Carnegie Mellon University