ADAS Subroutine effz3

       subroutine effz3( jealfa , n     , l      , e     , qd    ,
     &                   jsn    , z0    , nshell , nc    , numel ,
     &                   alfa   , jalf1 , jalf2  ,
     &                   x0     , x1    , x2     , d     , m0
     &                 )
C-----------------------------------------------------------------------
C
C  ****************** fortran77 program: effz3.for *********************
C
C  Purpose: Searches for the effective potential for a single electron
C           distorted wave function for a specified screening or a
C           specified energy.
C           (original by A. Burgess, DAMTP, University of Cambridge)
C
C
C  Subroutine:
C
C  input : (i*4)  jealfa   = <0 => search for energy e
C                          = >0 => search for screening parameter alfa
C  input : (i*4)  n        = principal quantum number
C  input : (i*4)  l        = orbital quantum number
C  i/o   : (i*4)  e        = energy (Ryd) for electron.
C                             (NB -ve for a bound state)
C  input : (i*4)  qd       = quantum defect for valence electron
C  input : (i*4)  jsn      = -1 => Jucys potential form adopted
C                          = 0  => Slater potential form adopted
C  input : (i*4)  z0       = nuclear charge
C  input : (i*4)  nshell   = number of screening shells
C  input : (i*4)  nc()     = principal quantum number of screening shell
C                            1st dim: index of screening shells
C  input : (i*4)  numel()  = number of electrons in screening shell
C  i/o   : (r*8)  alfa()   = screening parameters
C                            1st dim: initial (1) and final (2) states
C                            2nd dim: screening shell index.
C  input : (i*4)  jalf1    = first screening shell for optimising
C  input : (i*4)  jalf2    = last screening shell for optimising
C  output: (i*4)  x0       = inner turning point
C  output: (i*4)  x1       = outer turning point
C  output: (i*4)  x2       = range for active electron wave function
C  input : (i*4)  d        = earch accuracy setting
C  output: (i*4)  m0       = number of nodes in wave function
C
C
C
C  Routines:
C          routine    source    brief description
C          -------------------------------------------------------------
C          zeff       adas
C          zser       adas
C          fcf6       adas
C          i4unit     adas      fetch unit number for output of messages
C
C
C  Author:  H. P. Summers, University of Strathclyde
C           ja7.08
C           tel. 0141-548-4196
C
C  Date:   24/02/03
C
C  Update: HP Summers  24/05/04  restructure and addded standard warning
C
C-----------------------------------------------------------------------
      INTEGER             JALF1,       JALF2,       JEALFA,      JSN
      INTEGER             L,           M0,          N,           NC(10)
      INTEGER             NSHELL,      NUMEL(10)
      REAL*8              ALFA(10),    D,           E,           QD
      REAL*8              X0,          X1,          X2,          Z0