SUBROUTINE overlap_aph(sector_wf, sfunc, ndim_sec, overlap_element, whichir, nchir)

!=========================================================================================
! This routine otains the overlap of the Delves' "vibrational" functions with the 
!    propagated wave function at each time step.
! These will make up the F matrix elements at each energy after they have been Fourier 
!    transformed
!
! NOTE 2: These will be channel dependent when NOT dealing with an AAA system
!
! Variables:
!     Input
!       isf = the final state "vibrational" quantum number for the Delves' functions
!
!     Output
!       overlap_element = the overlap of a Delves' "vibrational" wave function of state f with 
!                     the propagated wave function at a particular time
!
!=========================================================================================

USE Numeric_Kinds_Module
USE CommonInfo_Module
USE APH_Module
USE Jacobi_Module
USE Delves_Module
USE Print_Module
!USE Overlap_Module
USE SymGroup_Module
USE SurfaceAPH_Module

IMPLICIT NONE

!=========================================================================================
!   I N P U T

INTEGER,INTENT(IN)     :: ndim_sec, whichir,nchir
REAL(dp),INTENT(IN)    :: sfunc(ndim_sec)
COMPLEX(dp),INTENT(INOUT) :: sector_wf(ndim_sec)

!=========================================================================================
!   O U T P U T

COMPLEX(dp),INTENT(OUT) :: overlap_element

!========================================================================================
!   I N T E R N A L S

INTEGER     :: itheta, ichi, sec_pt!, chishift
COMPLEX(dp) :: chi_sum, theta_sum

!=========================================================================================
!   A L L O C A T A B L E

!=========================================================================================
!   F U N C T I O N S

INTEGER :: aphindex_tc

!temp
!REAL(dp) theta_sum_real,theta_sum_imag,sec_real(ndim_sec),sec_imag(ndim_sec)

!=========================================================================================
!   N A M E L I S T S 

!========================================================================================
! Integrate

  overlap_element=Cmplx(0.d0,0.d0,dp)
  DO itheta=1,ndim_sec
    overlap_element=overlap_element+sector_wf(itheta)*sfunc(itheta)*deltachi
  ENDDO

!  sector_wf=sector_wf*sfunc*deltachi
!  overlap_element=SUM(sector_wf)

!==========================
! original method
!  theta_sum=0.d0

!   DO itheta=1,ntheta
 
!     chi_sum=0.d0
 
!     DO ichi=1,nchir

!       sec_pt=aphindex_tc(nchir,itheta,ichi)

!       chi_sum=chi_sum+sector_wf(sec_pt)*sfunc(sec_pt)*deltachi
!     ENDDO

!     theta_sum=theta_sum+chi_sum!*Sqrt(weights(itheta))

!   ENDDO

!   overlap_element=theta_sum

END SUBROUTINE overlap_aph