Gromacs TRR file reader — OVITO User Manual 3.16.0 documentation

# Gromacs TRR file reader

User interface of the Gromacs TRR file reader, which appears as part of a pipeline’s file source.

This file format is used by the GROMACS molecular dynamics code. A format specification can be found here.

Important

The file reader automatically converts atom coordinates and cell vectors from nanometers to Angstroms during import into OVITO, multiplying all values by a factor of 10. Velocities are converted from \(\mathrm{nm}/\mathrm{ps}\) to \(\text{Å}/\mathrm{ps}\), multiplying velocities by a factor of 10. Forces are converted from \(\mathrm{kJ} \mathrm{mol}^{-1} \mathrm{nm}^{-1}\) to \(\mathrm{eV}/\text{Å}\) using a factor of 0.00103643.

## Python parameters

The file reader accepts the following optional keyword parameters in a call to the `import_file()` or `load()` Python functions.

import_file(location, centering=True)
  Parameters:

    centering (bool) – If set to `True`, the simulation cell and all atomic coordinates are translated to center the box at the coordinate origin. If set to `False`, one corner of the simulation cell remains fixed at the coordinate origin.