.. _symmetrize_input:

SYMMETRIZE_INPUT
================

SYMMETRIZE_INPUT can be used to suppress recalculation of atom coordinates to
perfectly match a given symmetry. How much atoms might otherwise move is
defined by the tolerance :ref:`SYM_EPS`.

**Default**: SYMMETRIZE_INPUT = True (atom positions might be changed during
symmetry search)

**Syntax**:

::

   SYMMETRIZE_INPUT = False

**Acceptable values**: True, False, true, false, T, F, t, f (not case
sensitive)

SYMMETRIZE_INPUT might be used when a system does not entirely fulfil a given
symmetry (and should not be "corrected" to that symmetry), but the user still
wants to use symmetry detection with a large :ref:`SYM_EPS` in order to 
automatically move almost-symmetry-equivalent atoms in concert.
Similarly, SYMMETRIZE_INPUT could be used to avoid atoms snapping to a nearby
rotation axis or mirror plane. **Use of SYMMETRIZE_INPUT is discouraged,**
**unless you know what you are doing**

Note that SYMMETRIZE_INPUT does **not** prevent atoms from being linked by
symmetry during the search. If that is your goal, the parameter you want is
:ref:`ISYM`. If the symmetry is reduced or deactivated by
:ref:`ISYM`, symmetrization of atom positions will only be
performed for the reduced symmetry even if SYMMETRIZE_INPUT is True.