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qp2/plugins/local/tuto_plugins/tuto_I/traces_one_e.irp.f
2024-03-25 17:00:14 +01:00

112 lines
4.0 KiB
Fortran

! This file is an example of the kind of manipulations that you can do with providers
!
!!!!!!!!!!!!!!!!!!!!!!!!!! Main providers useful for the program !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! type name
BEGIN_PROVIDER [ double precision, trace_mo_one_e_ints]
implicit none
BEGIN_DOC
! trace_mo_one_e_ints = Trace of the one-electron integrals on the MO basis
!
! = sum_i mo_one_e_integrals(i,i)
END_DOC
integer :: i
trace_mo_one_e_ints = 0.d0
do i = 1, mo_num
trace_mo_one_e_ints += mo_one_e_integrals(i,i)
enddo
END_PROVIDER
BEGIN_PROVIDER [ double precision, trace_ao_one_e_ints]
implicit none
BEGIN_DOC
! trace_ao_one_e_ints = Trace of the one-electron integrals on the AO basis taking into account the non orthogonality
!
! Be aware that the trace of an operator in a non orthonormal basis is Tr(A S^{-1}) = \sum_{m,n}(A_mn S^{-1}_mn)
!
! WARNING: it is equal to the trace on the MO basis if and only if the AO basis and MO basis
! have the same number of functions
END_DOC
integer :: i,j
double precision, allocatable :: inv_overlap_times_integrals(:,:) ! = h S^{-1}
allocate(inv_overlap_times_integrals(ao_num,ao_num))
! routine that computes the product of two matrices, you can check it with
! irpman get_AB_prod
call get_AB_prod(ao_one_e_integrals,ao_num,ao_num,s_inv,ao_num,inv_overlap_times_integrals)
! Tr(inv_overlap_times_integrals) = Tr(h S^{-1})
trace_ao_one_e_ints = 0.d0
do i = 1, ao_num
trace_ao_one_e_ints += inv_overlap_times_integrals(i,i)
enddo
!
! testing the formula Tr(A S^{-1}) = \sum_{m,n}(A_mn S^{-1}_mn)
double precision :: test
test = 0.d0
do i = 1, ao_num
do j = 1, ao_num
test += ao_one_e_integrals(j,i) * s_inv(i,j)
enddo
enddo
if(dabs(accu - trace_ao_one_e_ints).gt.1.d-12)then
print*,'Warning ! '
print*,'Something is wrong because Tr(AB) \ne sum_{mn}A_mn B_nm'
endif
END_PROVIDER
BEGIN_PROVIDER [ double precision, trace_ao_one_e_ints_from_mo]
implicit none
BEGIN_DOC
! trace_ao_one_e_ints_from_mo = Trace of the one-electron integrals on the AO basis after projection on the MO basis
!
! = Tr([SC h {SC}^+] S^{-1})
!
! = Be aware that the trace of an operator in a non orthonormal basis is = Tr(A S^{-1}) where S is the metric
! Must be equal to the trace_mo_one_e_ints
END_DOC
integer :: i
double precision, allocatable :: inv_overlap_times_integrals(:,:)
allocate(inv_overlap_times_integrals(ao_num,ao_num))
! Using the provider ao_one_e_integrals_from_mo = [SC h {SC}^+]
call get_AB_prod(ao_one_e_integrals_from_mo,ao_num,ao_num,s_inv,ao_num,inv_overlap_times_integrals)
! inv_overlap_times_integrals = [SC h {SC}^+] S^{-1}
trace_ao_one_e_ints_from_mo = 0.d0
! Computing the trace
do i = 1, ao_num
trace_ao_one_e_ints_from_mo += inv_overlap_times_integrals(i,i)
enddo
END_PROVIDER
!!!!!!!!!!!!!!!!!!!!!!!!!!! Additional providers to check some stuffs !!!!!!!!!!!!!!!!!!!!!!!!!
BEGIN_PROVIDER [ double precision, ao_one_e_int_no_ov_from_mo, (ao_num, ao_num) ]
BEGIN_DOC
! ao_one_e_int_no_ov_from_mo = C mo_one_e_integrals C^T
!
! WARNING : NON EQUAL TO ao_one_e_integrals due to the non orthogonality
END_DOC
call mo_to_ao_no_overlap(mo_one_e_integrals,mo_num,ao_one_e_int_no_ov_from_mo,ao_num)
END_PROVIDER
BEGIN_PROVIDER [ double precision, ao_one_e_int_no_ov_from_mo_ov_ov, (ao_num, ao_num)]
BEGIN_DOC
! ao_one_e_int_no_ov_from_mo_ov_ov = S ao_one_e_int_no_ov_from_mo S = SC mo_one_e_integrals (SC)^T
!
! EQUAL TO ao_one_e_integrals ONLY IF ao_num = mo_num
END_DOC
double precision, allocatable :: tmp(:,:)
allocate(tmp(ao_num, ao_num))
call get_AB_prod(ao_overlap,ao_num,ao_num,ao_one_e_int_no_ov_from_mo,ao_num,tmp)
call get_AB_prod(tmp,ao_num,ao_num,ao_overlap,ao_num,ao_one_e_int_no_ov_from_mo_ov_ov)
END_PROVIDER
BEGIN_PROVIDER [ double precision, c_t_s_c, (mo_num, mo_num)]
implicit none
BEGIN_DOC
! C^T S C = should be the identity
END_DOC
call get_AB_prod(mo_coef_transp,mo_num,ao_num,S_mo_coef,mo_num,c_t_s_c)
END_PROVIDER