anchor.diff:  
   !$OMP DO
         do i=1,n2ft3d
  -       n        = rho_in(i) + ETA
  -       agr      = agr_in(i)
  -       n_thrd 	= n**thrd
  +       n      = rho_in(i) + ETA
  +       agr    = agr_in(i)
  +       n_thrd = n**thrd
   
          if (rho_in(i).lt.DNS_CUT) then
            xe     = 0.0d0
  
positive.code: 
  *      **************UP*******************
         chiup = agrup/nup**(4.0d0/3.0d0)
         chiup2 = chiup*chiup
         chiupSQ = dsqrt(1.0d0+chiup2)
  
         Kup = 6.0d0*beta*dlog(chiup+chiupSQ)
         F1up = chiup2/(1.0d0 + chiup*Kup)
         xeup = -nup**thrd*(lda_c + beta*F1up)
         F2up = (2.0d0 + chiup*Kup 
       &        - 6.0d0*beta*chiup2/chiupSQ)
       &        /(1.0d0+chiup*Kup)**2.0d0
         fdnxup = -nup**(thrd)*(4.0d0/3.0d0)
       &          *(lda_c+beta*(F1up-chiup2*F2up))
         fdagrxup = -beta*chiup*F2up 
  *      ************END UP*****************
  
  
  *      *************DOWN******************
         chidn = agrdn/ndn**(4.0d0/3.0d0)
         chidn2 = chidn*chidn
         chidnSQ = dsqrt(1.0d0+chidn2)
  
         Kdn = 6.0d0*beta*dlog(chidn+chidnSQ)
         F1dn = chidn2/(1.0d0 + chidn*Kdn)
         xedn = -ndn**thrd*(lda_c + beta*F1dn)
         F2dn = (2.0d0 + chidn*Kdn
       &        - 6.0d0*beta*chidn2/chidnSQ)
       &        /(1.0d0+chidn*Kdn)**2.0d0
         fdnxdn = -ndn**(thrd)*(4.0d0/3.0d0)
       &          *(lda_c+beta*(F1dn-chidn2*F2dn))
         fdagrxdn = -beta*chidn*F2dn
  
  
  *      ***********END DOWN****************
  
         xe = (xeup*nup + xedn*ndn)/n
  
  *      *******end excange part************
         end if
  
negative.code:       real*8 DNS_CUT, ETA
        parameter (DNS_CUT        =      1.0d-18)
        parameter (ETA            =      1.0d-20)
  
        real*8 tolrho,minagr
        parameter (tolrho=2.0e-8,minagr=1.0e-10)
  ****** Becke constants *****************************
        real*8 lda_c,beta
        parameter (beta = 0.0042d0)
  