Documentation update for --pretend_real

doc/command-options.rst

@@ -45,6 +45,7 @@ tags:
 * ``--pa``, ``--primitive_axis`` (``PRIMITIVE_AXIS``)
 * ``--pd``, ``--projection_direction`` (``PROJECTION_DIRECTION``)
 * ``--pdos`` (``PDOS``)
+* ``--pr``, ``--pretend_real`` (``PRETEND_REAL = .TRUE.``)
 * ``--q_direction`` (``Q_DIRECTION``)
 * ``--readfc`` (``FORCE_CONSTANTS = READ``)
 * ``--show_irreps`` (``SHOW_IRREPS``)

doc/introduction.rst

@@ -17,6 +17,8 @@ A presentation in pdf for introduction to phonopy is downloaded `***here***
 .. figure:: phonopy-slide-top.png
    :scale: 65
 
+.. _analyze_phonon:
+
 Features
 ---------
 

doc/setting-tags.rst

@@ -657,6 +657,18 @@ temperature range to be calculated. The default values of them are 0,
    TPROP = .TRUE.
    TMAX = 2000
 
+``PRETEND_REAL``
+~~~~~~~~~~~~~~~~~
+
+This enables to take imaginary frequencies as real for thermal
+property calculation. This does give false thermal properties,
+therefore for a testing purpose only, when a small amount of imaginary
+branches obtained.
+
+::
+
+   TPROP = .TRUE.
+   PRETEND_REAL = .TRUE.
 
 .. _thermal_atomic_displacements_tags: