anchor.diff:    use floatPrecision
     use numerical_constants
     use coll_materials, only : nmat
  +  use physical_constants, only : pmap
   
     implicit none
   
  
positive.code:   use coll_common, only : coll_debug
    use coll_crystal
    use coll_materials, only : nmat, rho, anuc, hcut, bnref, csref, csect
  
    implicit none
  
  
negative.code: 
    real(kind=fPrec), parameter :: re  = 2.818d-15   ! electron radius [m]
    real(kind=fPrec), parameter :: me  = 0.510998910 ! electron mass [MeV/c^2]
    real(kind=fPrec), parameter :: mp  = pmap  ! proton mass [MeV/c^2]
  
    real(kind=fPrec), parameter :: aTF = 0.194d-10   ! Screening function [m]
    real(kind=fPrec), parameter :: dP  = 1.92d-10    ! Distance between planes (110) [m]
  