The primary use of this script is as an alternative, Open, back-end to
Materials Studio's 'Calculate Elastic Constants' feature.

It was designed with CASTEP in mind, and only deals with the set of strains
that Materials Studio generates. As well as CASTEP's native formats, it also
accepts input in CML format, and can generate CML output. It also has the
option to generate an at-a-glance view, which allows the user to verify the
success, or otherwise, of all of the various linear fits.

It should be fairly easy to convert/generalize it for other strains and
simulation codes.


Supported Strain Patterns
-------------------------

Cubic: e1+e4
Hexagonal: e3 and e1+e4
Trigonal-High (32, 3m, -3m): e1 and e3+e4
Trigonal-Low (3, -3): e1 and e3+e4
Tetragonal: e1+e4 and e3+e6
Orthorhombic: e1+e4 and e2+e5 and e3+e6
Monoclinic: e1+e4 and e3+e6 and e2 and e5
Triclinic: e1 to e6 separately 

Dependencies
------------

The script is written in Python, so you must have that installed. I use Python 2.5, but earlier versions might work too. 

SciPy (http://www.scipy.org/)

NumPy (https://numpy.org)

(Optional) For CML input/output, you'll need Golem (http://www.lexical.org.uk/golem/), and lxml (http://codespeak.net/lxml/).

(Optional) For graphical output, you'll need Matplotlib (http://matplotlib.sourceforge.net/).