9
1
mirror of https://github.com/QuantumPackage/qp2.git synced 2024-07-19 17:23:25 +02:00
qp2/src/perturbation/README.rst
2019-01-25 11:39:31 +01:00

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