Pymatgen

* Beta new Gulp Caller and Zeo++ interface classes (Bharat . Zeo++ is an open
source software for performing high-throughput geometry-based analysis of
porous materials and their voids. Please see
<http://www.maciejharanczyk.info/Zeopp/about.html>.
* Specify version of distribute to 0.6.34 for better compatibility.

* Support for VTK 6.x in structure visualization.
* Updated install instructions for openbabel.
* Preliminary pourbaix analysis (Sai Jayaratnam).

* Vastly improved Nwchem IO (by Shyue Ping Ong).
* Much improved ABINIT support (by Matteo Giantomassi).

* Added basic Nwchem (<http://www.nwchem-sw.org/>) IO support. (by: Shyue Ping
Ong).
* New MoleculeMatcher class for comparing molecules by RMS. Requires
openbabel with python bindings. (by: Xiaohui Qu)
* New functional group substitution capability for molecules (by: Lei Cheng
and Shyue Ping Ong).

* Minor bug fix release to fix some rare errors in very high dimensional
phase diagrams. **Requires new pyhull version (1.3.8).**

* **Major backwards-incompatible change.** With effect from v2.7.1,
the default Structure and Molecule classes are now _mutable_ objects. All
functionality in the :mod:`pymatgen.core.structure_modifier` has been
ported over to the new mutable classes. This change was implemented
because the immutability of Structure and Molecule has resulted in very
awkward code to make changes to them. The main cost of this change is that
Structure and Molecule can no longer be used as dict keys (**hash** has
been set to None). However, we believe this is a minor cost given that we
have rarely seen the use of Structure or Molecule as dict keys in any case.
For the rare instances where such functionality is needed,
we have provided the IStructure and IMolecule classes (where I indicates
immutability) which will perform exactly the same way as the previous
classes. With this change, the :mod:`pymatgen.core.structure_modifier`
module is now deprecated and will be removed in a future version.
* read_structure and write_structure now supports pymatgen's JSON-serialized
structures.
* read_mol and write_mol functions now available (analogues of
read_structure and write_structure for molecules)