Model Hamiltonian

• A choice of Density Functionals, both for the Local Density Approximation (LDA),
  for the Generalized Gradient Approximation (GGA),
  for hybrid functionals (currently for the SCF and energies only, not for geometry optimizations, for example),
  and for meta-GGA functionals (currently for energies only) are available.
• Spin: restricted or unrestricted
• Relativistic effects: scalar approximation and spin-orbit (double-group symmetry),
  using the (now recommended) ZORA or the (previously used) Pauli formalism
• Environment: Solvent Effects, Homogeneous Electric Field, Point Charges (Madelung Fields),
  QM/MM method