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8f89e3d239
* Documentation * Improved qp_set_frozen_core * Changed all ishft * New install script OK * Variable level shift in HF
98 lines
2.2 KiB
ReStructuredText
98 lines
2.2 KiB
ReStructuredText
.. _hartree_fock:
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.. program:: hartree_fock
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.. default-role:: option
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============
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Hartree-Fock
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============
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The Hartree-Fock module performs *Restricted* Hartree-Fock calculations (the
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spatial part of the |MOs| is common for alpha and beta spinorbitals).
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The Hartree-Fock program does the following:
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#. Compute/Read all the one- and two-electron integrals, and store them in memory
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#. Check in the |EZFIO| database if there is a set of |MOs|. If there is, it
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will read them as initial guess. Otherwise, it will create a guess.
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#. Perform the |SCF| iterations
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At each iteration, the |MOs| are saved in the |EZFIO| database. Hence, if the calculation
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crashes for any unexpected reason, the calculation can be restarted by running again
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the |SCF| with the same |EZFIO| database.
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The `DIIS`_ algorithm is implemented, as well as the `level-shifting`_ method.
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If the |SCF| does not converge, try again with a higher value of :option:`level_shift`.
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To start a calculation from scratch, the simplest way is to remove the
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``mo_basis`` directory from the |EZFIO| database, and run the |SCF| again.
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.. _DIIS: https://en.wikipedia.org/w/index.php?title=DIIS
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.. _level-shifting: https://doi.org/10.1002/qua.560070407
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EZFIO parameters
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----------------
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.. option:: max_dim_diis
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Maximum size of the |DIIS| extrapolation procedure
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Default: 15
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.. option:: threshold_diis
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Threshold on the convergence of the |DIIS| error vector during a Hartree-Fock calculation. If 0. is chosen, the square root of thresh_scf will be used.
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Default: 0.
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.. option:: thresh_scf
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Threshold on the convergence of the Hartree Fock energy.
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Default: 1.e-10
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.. option:: n_it_scf_max
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Maximum number of |SCF| iterations
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Default: 500
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.. option:: level_shift
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Energy shift on the virtual |MOs| to improve |SCF| convergence
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Default: 0.2
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.. option:: scf_algorithm
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Type of |SCF| algorithm used. Possible choices are [ Simple | DIIS]
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Default: DIIS
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.. option:: mo_guess_type
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Initial MO guess. Can be [ Huckel | HCore ]
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Default: Huckel
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.. option:: energy
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Calculated HF energy
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.. option:: no_oa_or_av_opt
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If true, skip the (inactive+core) --> (active) and the (active) --> (virtual) orbital rotations within the |SCF| procedure
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Default: False
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