SUBROUTINE diatomic_v(s,v,ichanl)
!
!==============================================================================================
! This routine obtains a value of the diatomic potential at a given Jacobi Mass-Scaled s value.
!==============================================================================================
!
USE Numeric_Kinds_Module
USE CommonInfo_Module
USE Jacobi_Module
Use Das_Module
IMPLICIT NONE
!
! Set two of the interparticle separations to very large values to obtain the asymptotic diatomic potential
! Let r(1) be the diatomic internuclear distance

!=========================================================================================
!  I N P U T
REAL(dp),INTENT(IN) :: s
INTEGER :: ichanl

!=========================================================================================
!  O U T P U T
REAL(dp),INTENT(OUT) :: v

!=========================================================================================
!  I N T E R N A L S
REAL(dp) :: r(3)  ! Interparticle separations

!=========================================================================================
! Unscale Jacobi s coordinate and assign it to r(1). Scaling coefficient is d
! Set two of the interparticle separations to large values

IF (ichanl.eq.1) THEN

  r(1)=dscale(1)*s
  r(2)=1.d30
  r(3)=1.d30

ELSEIF (ichanl.eq.2) THEN

  r(2)=dscale(2)*s
  r(3)=1.d30
  r(1)=1.d30

ELSEIF (ichanl.eq.3) THEN

  r(3)=dscale(3)*s
  r(1)=1.d30
  r(2)=1.d30

ENDIF
!===============================================
! Obtain value of the diatomic potential at r(1)

CALL surface(v,r)


END SUBROUTINE diatomic_v