[gmx-users] trajectory file formats

[Jim Kress]

I have written a unique MD program and want to output a full-precision
trajectory containing coordinate, velocity, and force information in a .trr
or a .trj formatted file.  

Where in the gromacs code can I find a description of the formats of these
files and an example of how they are written?

Alternately, I can write .gro files and append the force information in the
same format as the velocity information.  Will the gromacs utilities ignore
the extra information in the generated .gro files or will it cause them to
fail?

Any advice/ suggestions would be appreciated.

Thanks.

Jim