v2.6.0

• New features
  • Complete rewrite of the Atoms and SCF classes
    • Easily allow systems with different charge or multiplicity
    • Document all public properties
    • Use properties when parsing input arguments
    • Allow direct setting of attributes
    • Better input handling
    • Use an Occupations object to store electronic states information in Atoms
    • Use a GTH object to store GTH data in SCF
    • Add some properties to the objects, e.g., the volume element dV in Atoms
    • Indicate non-input arguments and non-results as private or read-only
    • Breaking:
      • Use unrestricted instead of Nspin
      • Use spin and charge instead of Nstate and f
      • Remove f and s as keyword arguments, can be set after initialization
      • Remove cgform as a keyword argument, use the run function to pass it to minimizers
      • Rename min keyword to opt
      • Merge symmetric with guess
  • Add DFT-D3 dispersion correction as an extra
• Updated docs
  • Add a theory introduction page
  • Add documentation to module data/constants
  • Add a list of all packages and their respective licenses
  • Re-add documentation of operators to Atoms
  • Add a custom functional example
  • Improve the geometry optimization example
  • Add PNGs to the downloads section
  • Sort attributes groupwise
  • Fix a lot of typos
• Coding style
  • Type check with mypy
  • Fix a lot of type warnings from mypy
  • Add type hints to scripts in docs and setup.py
  • Rename some arguments to not shadow builtins
• Miscellaneous
  • Create the eminus-benchmarks repository
    • Move the SimpleDFT example to said repository
  • Small performance improvements, mostly for meta-GGAs
  • Add an error message when attempting to use operators of an unbuilt Atoms object
  • Add Matplotlib to the viewer setup to generate images in the examples
  • More tests, e.g, for different spin and charge states
  • Add a small demo function