anchor.diff:  
     ! New treatment of scattering routine based on standard sixtrack routine
     ! useful calculations for cross-section and event topology calculation
  -  ecmsq  = two*0.93828_fPrec*pc
  +  ecmsq  = two*pmap*c1m3*pc
     xln15s = log(0.15*ecmsq)
   
     ! New models, see Claudia's thesis
  
positive.code:   x_i = x_i - Np*dP    ! Rescale the incoming x at the left crystalline plane
    x_i = x_i - (dP/two) ! Rescale the incoming x in the middle of crystalline planes
  
    pv   = pc*c1e9*pc*c1e9/sqrt(pc*c1e9*pc*c1e9 + 93828.0e6_fPrec*93828.0e6_fPrec) ! Calculate pv=P/E
    Ueff = eUm(is)*(two*x_i/dp)*(two*x_i/dp)+pv*x_i/r                              ! Calculate effective potential
    Et   = pv*xp*xp/two+Ueff                                                       ! Calculate transverse energy
    Ec   = eUm(is)*(one-rc/r)*(one-rc/r)                                           ! Calculate critical energy in bent crystals
  
    ! To avoid negative Et
    xminU = -dp*dp*pc*c1e9/(eight*eUm(is)*r)
  
negative.code:   use coll_common, only : coll_debug
    use coll_crystal
    use coll_materials, only : nmat, rho, anuc, hcut, bnref, csref, csect
    use physical_constants
  
    implicit none
  
  