mirror of
https://github.com/LCPQ/quantum_package
synced 2024-09-27 20:11:25 +02:00
110 lines
2.7 KiB
ReStructuredText
110 lines
2.7 KiB
ReStructuredText
|
.. _perturbation:
|
||
|
|
|
||
|
|
.. program:: perturbation
|
||
|
|
|
||
|
|
.. default-role:: option
|
||
|
|
|
||
|
|
============
|
||
|
|
Perturbation
|
||
|
|
============
|
||
|
|
|
||
|
|
|
||
|
|
All subroutines in ``*.irp.f`` starting with `pt2_` in the current directory are
|
||
|
|
perturbation computed using the routine `i_H_psi`. Other cases are not allowed.
|
||
|
|
The arguments of the `pt2_` are always:
|
||
|
|
|
||
|
|
.. code-block:: fortran
|
||
|
|
|
||
|
|
subroutine pt2_...( &
|
||
|
|
psi_ref, &
|
||
|
|
psi_ref_coefs, &
|
||
|
|
E_refs, &
|
||
|
|
det_pert, &
|
||
|
|
c_pert, &
|
||
|
|
e_2_pert, &
|
||
|
|
H_pert_diag, &
|
||
|
|
Nint, &
|
||
|
|
Ndet, &
|
||
|
|
N_st )
|
||
|
|
|
||
|
|
|
||
|
|
integer , intent(in) :: Nint,Ndet,N_st
|
||
|
|
integer(bit_kind), intent(in) :: psi_ref(Nint,2,Ndet)
|
||
|
|
double precision , intent(in) :: psi_ref_coefs(Ndet,N_st)
|
||
|
|
double precision , intent(in) :: E_refs(N_st)
|
||
|
|
integer(bit_kind), intent(in) :: det_pert(Nint,2)
|
||
|
|
double precision , intent(out) :: c_pert(N_st),e_2_pert(N_st),H_pert_diag
|
||
|
|
|
||
|
|
|
||
|
|
`psi_ref`
|
||
|
|
bitstring of the determinants present in the various `N_st` states
|
||
|
|
|
||
|
|
`psi_ref_coefs`
|
||
|
|
coefficients of the determinants on the various `N_st` states
|
||
|
|
|
||
|
|
`E_refs`
|
||
|
|
Energy of the various `N_st` states
|
||
|
|
|
||
|
|
`det_pert`
|
||
|
|
Perturber determinant
|
||
|
|
|
||
|
|
`c_pert`
|
||
|
|
Perturbative coefficients for the various states
|
||
|
|
|
||
|
|
`e_2_pert`
|
||
|
|
Perturbative energetic contribution for the various states
|
||
|
|
|
||
|
|
`H_pert_diag`
|
||
|
|
Diagonal |H| matrix element of the perturber
|
||
|
|
|
||
|
|
`Nint`
|
||
|
|
Should be equal to `N_int`
|
||
|
|
|
||
|
|
`Ndet`
|
||
|
|
Number of determinants `i` in |Psi| on which we apply <det_pert | |H| | `i`>
|
||
|
|
|
||
|
|
`N_st`
|
||
|
|
Number of states
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
EZFIO parameters
|
||
|
|
----------------
|
||
|
|
|
||
|
|
.. option:: do_pt2
|
||
|
|
|
||
|
|
If `True`, compute the |PT2| contribution
|
||
|
|
|
||
|
|
Default: True
|
||
|
|
|
||
|
|
.. option:: PT2_max
|
||
|
|
|
||
|
|
The selection process stops when the largest |PT2| (for all the state) is lower
|
||
|
|
|
||
|
|
than `pt2_max` in absolute value
|
||
|
|
|
||
|
|
Default: 0.0001
|
||
|
|
|
||
|
|
.. option:: PT2_relative_error
|
||
|
|
|
||
|
|
Stop stochastic |PT2| when the relative error is smaller than `PT2_relative_error`
|
||
|
|
|
||
|
|
Default: 0.005
|
||
|
|
|
||
|
|
.. option:: correlation_energy_ratio_max
|
||
|
|
|
||
|
|
The selection process stops at a fixed correlation ratio (useful for getting same accuracy between molecules).
|
||
|
|
|
||
|
|
Defined as :math:`{E_{CI}-E_{HF}}/{E_{CI}+E_{PT2} - E_{HF}}`.
|
||
|
|
|
||
|
|
Default: 1.00
|
||
|
|
|
||
|
|
.. option:: h0_type
|
||
|
|
|
||
|
|
Type of zeroth-order Hamiltonian [ EN | Barycentric | Variance ]
|
||
|
|
|
||
|
|
Default: EN
|