mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-11-06 05:23:37 +01:00
87 lines
2.4 KiB
Fortran
87 lines
2.4 KiB
Fortran
program scf
|
|
BEGIN_DOC
|
|
!
|
|
! The :ref:`scf` program performs *Restricted* Hartree-Fock
|
|
! calculations (the spatial part of the |MOs| is common for alpha and beta
|
|
! spinorbitals).
|
|
!
|
|
! It performs the following actions:
|
|
!
|
|
! #. Compute/Read all the one- and two-electron integrals, and store them
|
|
! in memory
|
|
! #. Check in the |EZFIO| database if there is a set of |MOs|.
|
|
! If there is, it will read them as initial guess. Otherwise, it will
|
|
! create a guess.
|
|
! #. Perform the |SCF| iterations
|
|
!
|
|
! For the keywords related to the |SCF| procedure, see the ``scf_utils``
|
|
! directory where you will find all options.
|
|
!
|
|
! At each iteration, the |MOs| are saved in the |EZFIO| database. Hence,
|
|
! if the calculation crashes for any unexpected reason, the calculation
|
|
! can be restarted by running again the |SCF| with the same |EZFIO|
|
|
! database.
|
|
!
|
|
! To start again a fresh |SCF| calculation, the |MOs| can be reset by
|
|
! running the :ref:`qp_reset` command.
|
|
!
|
|
! The `DIIS`_ algorithm is implemented, as well as the `level-shifting`_
|
|
! method. If the |SCF| does not converge, try again with a higher value of
|
|
! :option:`level_shift`.
|
|
!
|
|
! .. _DIIS: https://en.wikipedia.org/w/index.php?title=DIIS
|
|
! .. _level-shifting: https://doi.org/10.1002/qua.560070407
|
|
!
|
|
END_DOC
|
|
call create_guess
|
|
call orthonormalize_mos
|
|
call run
|
|
end
|
|
|
|
subroutine create_guess
|
|
implicit none
|
|
BEGIN_DOC
|
|
! Create a MO guess if no MOs are present in the EZFIO directory
|
|
END_DOC
|
|
logical :: exists
|
|
PROVIDE ezfio_filename
|
|
call ezfio_has_mo_basis_mo_coef(exists)
|
|
if (.not.exists) then
|
|
if (mo_guess_type == "HCore") then
|
|
mo_coef = ao_ortho_lowdin_coef
|
|
TOUCH mo_coef
|
|
mo_label = 'Guess'
|
|
call mo_as_eigvectors_of_mo_matrix(mo_one_e_integrals, &
|
|
size(mo_one_e_integrals,1), &
|
|
size(mo_one_e_integrals,2), &
|
|
mo_label,1,.false.)
|
|
SOFT_TOUCH mo_coef mo_label
|
|
else if (mo_guess_type == "Huckel") then
|
|
call huckel_guess
|
|
else
|
|
print *, 'Unrecognized MO guess type : '//mo_guess_type
|
|
stop 1
|
|
endif
|
|
endif
|
|
end
|
|
|
|
subroutine run
|
|
|
|
BEGIN_DOC
|
|
! Run SCF calculation
|
|
END_DOC
|
|
|
|
use bitmasks
|
|
implicit none
|
|
|
|
integer :: i_it, i, j, k
|
|
|
|
mo_label = "Orthonormalized"
|
|
|
|
call Roothaan_Hall_SCF
|
|
call ezfio_set_hartree_fock_energy(SCF_energy)
|
|
|
|
end
|
|
|
|
|