ADAS Subroutine nhydes

       SUBROUTINE NHYDES(Z0,ZEFF,N,L,E0)
       IMPLICIT REAL*8(A-H,O-Z)
C-----------------------------------------------------------------------
C
C  PURPOSE: CALULATES LOWEST ORDER NON-RELATIVISTIC, RELATIVISTIC AND
C           QUANTUM-ELECTRODYNAMIC ENERGIES FOR HYDROGENIC IONS
C
C  BINDING ENERGY FOR CENTRE OF TERM IS PRODUCED.  FINE STRUCTURE FOR
C  L>0 MUST BE ADDED EXTERNALLY. FORMULAE ARE FROM ERIKSON (1977) J.PHY
C  CHEM. REF.DATA,6,831.
C  QED EFFECTS FOR L>0 OMITTED.
C-----------------------------------------------------------------------
C VERSION  : 1.1
C DATE     : 18-03-1999
C MODIFIED : ???
C
C VERSION  : 1.2
C DATE     : 05-10-2000
C MODIFIED : ???
C             - Removed junk from columns > 72
C
C VERSION  : 1.3
C DATE     : 16-05-2007
C MODIFIED : Allan Whiteford
C             - Updated comments as part of subroutine documentation
C               procedure.
C
C-----------------------------------------------------------------------
      INTEGER             L,           N
      REAL*8              E0,          Z0,          ZEFF