mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-09-01 16:53:50 +02:00
65 lines
1.8 KiB
ReStructuredText
65 lines
1.8 KiB
ReStructuredText
|
============
|
||
|
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
|
||
|
|
||
|
|
||
|
|