cosmetic corrections

to the current force vector and hard-coded minimization parameters.

A complete description of the differences between *fire/old* and *fire*

can be found in :ref:`(Guenole) <Guenole>` (where the current *fire*

in lammps is named *fire2.0*). By using an appropriate set of 

parameters, *fire* can behave similarly than *fire/old*, as described

in LAMMPS is called *fire2.0*). By using an appropriate set of

parameters, *fire* can behave similar to *fire/old*, as described

in the :doc:`min_modify <min_modify>` command.

Style *spin* is a damped spin dynamics with an adaptive timestep.