General properties ------------------ | :ref:`gmx energy `, :ref:`gmx traj ` | To analyze some or all *energies* and other properties, such as *total pressure*, *pressure tensor*, *density*, *box-volume* and *box-sizes*, use the program :ref:`gmx energy `. A choice can be made from a list a set of energies, like potential, kinetic or total energy, or individual contributions, like Lennard-Jones or dihedral energies. The *center-of-mass velocity*, defined as .. math:: {\bf v}_{com} = {1 \over M} \sum_{i=1}^N m_i {\bf v}_i :label: eqncomvelocity with :math:`M = \sum_{i=1}^N m_i` the total mass of the system, can be monitored in time by the program :ref:`gmx traj ` ``-com -ov``. It is however recommended to remove the center-of-mass velocity every step (see chapterĀ :ref:`algorithms`)!