Pymatgen

* PR 2130 rkingsbury ensures that energy corrections applied to each anion
have unique names (e.g., N vs. Cl vs. Br).
* PR 2133 rkingsbury adds support for custom vdW radii to `QCInput` and
`QChemDictSet`. These radii are used in the construction of PCM cavities and
when calculating charges.
* PR 2123 from gpetretto fixes bug in `get_conventional_standard_structure`
method of the `SpacegroupAnalyzer` for triclinic crystals.
* PR 2134 from ab5424 supports zopen in parsing lammps logs
* PR 2132 from htz1992213 speeds up LammpsData.as_string for
non-hybrid data with large coeff sections and adds as_lammpsdata method to
CombinedData
* PR 2129 from CifLord improves analysis of surface symmetry of slabs.
* PR 2117 from nwinner contains bug fixes for bader caller.

* Improved Gaussian Cube I/O (nwinner, 2121)
* Updated van der Waals radii (rkingsbury, 2122)
* Update `MaterialsProject2020Compatibility` for multi-anion systems (rkingsbury, 2128)
* Fixes and improvements to Q-Chem parsing (samblau, 2125)
* Bug fix for isseus with hard-coded path in `MaterialsProject2020Compatibility` (CompRhys, 2124)
* Bug fix for DOS serialization (zooks97, 2119)
* Bug fix for XDATCAR lattice parsing (nkeilbart, 2115)
* Documentation link fix (adam-kerrigan, 2127)

* Feature to calculate Selling vectors and distances between Lattices (bwjustus, 1888)
* XPS Spectrum class added (shyuep, 2110, see `galore <https://github.com/SMTG-UCL/galore>`\_)
* Updated `MaterialsProject2020Compatibility` for formation energy correction (rkingsbury, 2106)
* Bug fix for detecting broken bonds in slab generation (fyalcin, 2015)
* Bug fix for electrodes (jmmshn, 2101)
* Documentation improvement for get_conventional_standard_structure (tom-wood, 2100)

* Bug fix to remove possibility of duplicate edges in `StructureGraph` (mkhorton, 2095)

* Element now has `ionization_energies`, `ionization_energy` and
`electron_affinity` properties.
* Extensive documentation has been added on pymatgen compatibility and the
new namespace architecture! We have also released a
`template repo <https://github.com/materialsproject/pymatgen-addon-template>`\_
to help new developers write add-ons for pymatgen! Check out our
:doc:`contributing page</contributing>` for details.

* Another bug fix release! Now SETTINGS have been moved to pymatgen.core.