TheoryLevel

TheoryLevel

Section Hamiltonian
Type integer

The calculations can be run with different "theory levels" that control how electrons are simulated. The default is dft. When hybrid functionals are requested, through the XCFunctional variable, the default is hartree_fock.

Options:

• independent_particles:
  Particles will be considered as independent, i.e. as non-interacting. This mode is mainly used for testing purposes, as the code is usually much faster with independent_particles.
  
• hartree:
  Calculation within the Hartree method (experimental). Note that, contrary to popular belief, the Hartree potential is self-interaction-free. Therefore, this run mode will not yield the same result as kohn-sham without exchange-correlation.
  
• hartree_fock:
  This is the traditional Hartree-Fock scheme. Like the Hartree scheme, it is fully self-interaction-free.
  
• kohn_sham:
  This is the default density-functional theory scheme. Note that you can also use hybrid functionals in this scheme, but they will be handled the "DFT" way, i.e., solving the OEP equation.
  
• generalized_kohn_sham:
  This is similar to the kohn-sham scheme, except that this allows for nonlocal operators. This is the default mode to run hybrid functionals, meta-GGA functionals, or DFT+U. It can be more convenient to use kohn-sham DFT within the OEP scheme to get similar (but not the same) results. Note that within this scheme you can use a correlation functional, or a hybrid functional (see XCFunctional). In the latter case, you will be following the quantum-chemistry recipe to use hybrids.
  
• rdmft:
  (Experimental) Reduced Density Matrix functional theory.
  

 call parse_variable(namespace, 'TheoryLevel', default, ks%theory_level)