anchor.diff:      E3 = E2 * E(K)
       S4 = S4 + E3
   
  -    DO L= 1, NATOM
  +    DO L = 1, NATOM
           EL2 = E(L)**2
           IF (K .LT. L) THEN
               D2 = 0.0
  
positive.code: END DO
  
  NATOM = N - 1
  WRITE(6,325) NATOM
  
  EPS = 10.0**(-NEPS)
  S1 = 0.0
  
negative.code: WRITE(6,"(A,/)") " FRCC: THIS VERSION 11.11.2013"
  
  DO N=1,2000
      READ(5, "(4F10.2)", IOSTAT=IERR) (R(N,J),J=1,3),E(N)
  
      IF (IERR .LT. 0) THEN
          EXIT
  