.. _MOLSYM:

``MOLSYM``
==========

Print details of the working in MOLSYM, the routine that works out the
symmetry point-group of the molecule.  Point-groups are identified using
a set of 20 integers.  These are 0 if the associated operation is
absent, 1 if the operation is present.  The operations are:

.. raw:: html

   <div align="center">

+-----------------------------------+-----------------------------------+
| Operation                         | Operation                         |
|                                   |                                   |
| Number                            |                                   |
+-----------------------------------+-----------------------------------+
| 1                                 | C\ :sub:`2`\ (X)                  |
+-----------------------------------+-----------------------------------+
| 2                                 | C\ :sub:`2`\ (Y)                  |
+-----------------------------------+-----------------------------------+
| 3                                 | C\ :sub:`2`\ (Z)                  |
+-----------------------------------+-----------------------------------+
| 4                                 | Σ(XY)                             |
+-----------------------------------+-----------------------------------+
| 5                                 | Σ(XZ)                             |
+-----------------------------------+-----------------------------------+
| 6                                 | Σ(YZ)                             |
+-----------------------------------+-----------------------------------+
| 7                                 | inversion                         |
+-----------------------------------+-----------------------------------+
| 8                                 | C\ :sub:`3`                       |
+-----------------------------------+-----------------------------------+
| 9                                 | C\ :sub:`4`                       |
+-----------------------------------+-----------------------------------+
| 10                                | C\ :sub:`3`                       |
+-----------------------------------+-----------------------------------+
| 11                                | C\ :sub:`6`                       |
+-----------------------------------+-----------------------------------+
| 12                                | C\ :sub:`3`                       |
+-----------------------------------+-----------------------------------+
| 13                                | C\ :sub:`8`                       |
+-----------------------------------+-----------------------------------+
| 14                                | S\ :sub:`4`                       |
+-----------------------------------+-----------------------------------+
| 15                                | S\ :sub:`6`                       |
+-----------------------------------+-----------------------------------+
| 16                                | S\ :sub:`8`                       |
+-----------------------------------+-----------------------------------+
| 17                                | S\ :sub:`10`                      |
+-----------------------------------+-----------------------------------+
| 18                                | S\ :sub:`12`                      |
+-----------------------------------+-----------------------------------+
| 19                                | 1 if cubic                        |
+-----------------------------------+-----------------------------------+
| 20                                | 1 if infinite                     |
+-----------------------------------+-----------------------------------+

.. raw:: html

   </div>

| A tetrahedral molecule, for example, would have the pattern: 
|  

.. raw:: html

   <div align="center">

+-----------+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
| Operation |  1 |  2 |  3 |  4 |  5 |  6 |  7 |  8 |  9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
+-----------+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
| Value     | 0  | 0  | 1  | 0  | 1  | 1  | 0  | 1  | 0  | 0  | 0  | 0  | 0  | 1  | 0  | 0  | 0  | 0  | 1  | 0  |
+-----------+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+

.. raw:: html

   </div>

This indicates that operations C\ :sub:`2`\ (Z), Σ(XZ), Σ(YZ),
C\ :sub:`3`, and S\ :sub:`4` are present, and that the system is cubic.

The pattern of operations is unique for each point-group, and is used by
subroutine cartab to identify the point-group.