@staticmethod
def rename_energies(gmx_energy):
    """Rename GROMACS energy terms to PyRETIS convention."""
    energy_map = {'potential': 'vpot', 'kinetic en.': 'ekin', 'temperature':
        'temp', 'total energy': 'etot', 'pressure': 'press'}
    energy = {}
    for key, val in gmx_energy.items():
        name = energy_map.get(key, key)
        energy[name] = val[0]
    return energy
