anchor.diff:    real(kind=fPrec) Pvr                  ! Prob for VR->AM transition
   
     real(kind=fPrec) const_dech,xpin,ypin,tchan,L_chan,mep
  +  real(kind=fPrec) s_K,x_K,s_M,x_M,s_F,x_F,r,a
  +  real(kind=fPrec) A_F,B_F,C_F,alpha_F,beta_F
   
     real(kind=fPrec), parameter :: c_v1 =  1.7_fPrec ! Fitting coefficient
     real(kind=fPrec), parameter :: c_v2 = -1.5_fPrec ! Fitting coefficient
  
positive.code:   real(kind=fPrec), intent(inout) :: yp
    real(kind=fPrec), intent(inout) :: pc
    real(kind=fPrec), intent(in)    :: length
  
    integer nam,zn                        ! Switch on/off the nuclear interaction (NAM) and the MCS (ZN)
    real(kind=fPrec) ymax,ymin            ! Crystal geometrical parameters
  
negative.code:   xp_tangent = zero
    tilt_int   = zero
    shift      = zero
    delta      = zero
    a_eq       = zero
    b_eq       = zero
    c_eq       = zero
    s_imp      = zero
  
  
    ! Determining if particle previously interacted with a crystal and storing the process ID
    if(cry_proc_tmp(j) /= proc_out) then
  