2014-05-17 14:20:55 +02:00
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===================
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Perturbation Module
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===================
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All subroutines in `*.irp.f` starting with ``pt2_`` in the current directory are
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perturbation computed using the routine ``i_H_psi``. Other cases are not allowed.
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The arguments of the ``pt2_`` are always:
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subroutine pt2_...( &
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psi_ref, &
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psi_ref_coefs, &
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E_refs, &
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det_pert, &
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c_pert, &
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e_2_pert, &
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H_pert_diag, &
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Nint, &
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ndet, &
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n_st )
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integer, intent(in) :: Nint,ndet,n_st
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integer(bit_kind), intent(in) :: psi_ref(Nint,2,ndet)
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double precision , intent(in) :: psi_ref_coefs(ndet,n_st)
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double precision , intent(in) :: E_refs(n_st)
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integer(bit_kind), intent(in) :: det_pert(Nint,2)
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double precision , intent(out) :: c_pert(n_st),e_2_pert(n_st),H_pert_diag
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psi_ref
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bitstring of the determinants present in the various n_st states
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psi_ref_coefs
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coefficients of the determinants on the various n_st states
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E_refs
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Energy of the various n_st states
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det_pert
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Perturber determinant
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c_pert
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Pertrubative coefficients for the various states
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e_2_pert
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Perturbative energetic contribution for the various states
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H_pert_diag
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Diagonal H matrix element of the perturber
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Nint
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Should be equal to N_int
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Ndet
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Number of determinants `i` in Psi on which we apply <det_pert|Hi>
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N_st
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Number of states
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Assumptions
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===========
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.. Do not edit this section. It was auto-generated from the
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.. NEEDED_MODULES file.
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* This is not allowed:
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subroutine &
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pt2_....
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Documentation
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=============
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.. Do not edit this section. It was auto-generated from the
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.. NEEDED_MODULES file.
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2014-05-21 16:37:54 +02:00
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`pt2_epstein_nesbet <http://github.com/LCPQ/quantum_package/tree/master/src/Perturbation/epstein_nesbet.irp.f#L1>`_
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compute the standard Epstein-Nesbet perturbative first order coefficient and second order energetic contribution
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.br
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for the various n_st states.
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.br
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c_pert(i) = <psi(i)|H|det_pert>/( E(i) - <det_pert|H|det_pert> )
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.br
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e_2_pert(i) = <psi(i)|H|det_pert>^2/( E(i) - <det_pert|H|det_pert> )
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.br
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`pt2_epstein_nesbet_2x2 <http://github.com/LCPQ/quantum_package/tree/master/src/Perturbation/epstein_nesbet.irp.f#L33>`_
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compute the Epstein-Nesbet 2x2 diagonalization coefficient and energetic contribution
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.br
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for the various n_st states.
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.br
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e_2_pert(i) = 0.5 * (( <det_pert|H|det_pert> - E(i) ) - sqrt( ( <det_pert|H|det_pert> - E(i)) ^2 + 4 <psi(i)|H|det_pert>^2 )
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.br
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c_pert(i) = e_2_pert(i)/ <psi(i)|H|det_pert>
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.br
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2014-05-17 14:20:55 +02:00
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Needed Modules
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==============
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.. Do not edit this section. It was auto-generated from the
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.. NEEDED_MODULES file.
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* `AOs <http://github.com/LCPQ/quantum_package/tree/master/src/AOs>`_
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* `BiInts <http://github.com/LCPQ/quantum_package/tree/master/src/BiInts>`_
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* `Bitmask <http://github.com/LCPQ/quantum_package/tree/master/src/Bitmask>`_
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* `Dets <http://github.com/LCPQ/quantum_package/tree/master/src/Dets>`_
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* `Electrons <http://github.com/LCPQ/quantum_package/tree/master/src/Electrons>`_
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* `Ezfio_files <http://github.com/LCPQ/quantum_package/tree/master/src/Ezfio_files>`_
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* `Hartree_Fock <http://github.com/LCPQ/quantum_package/tree/master/src/Hartree_Fock>`_
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* `MonoInts <http://github.com/LCPQ/quantum_package/tree/master/src/MonoInts>`_
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* `MOs <http://github.com/LCPQ/quantum_package/tree/master/src/MOs>`_
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* `Nuclei <http://github.com/LCPQ/quantum_package/tree/master/src/Nuclei>`_
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* `Output <http://github.com/LCPQ/quantum_package/tree/master/src/Output>`_
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* `Utils <http://github.com/LCPQ/quantum_package/tree/master/src/Utils>`_
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