ADAS Subroutine cxghnl

      SUBROUTINE CXGHNL ( MXNSHL , IZ1    , IZEFF  , N      ,
     &                    L      , N1     , TEV    , GAMA
     &                  )
C
C
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: CXGHNL *********************
C
C  PURPOSE:  CALCULATES APPROXIMATE EXCITATION RATE PARAMETERS FROM
C            N,L LEVELS OF HYDROGEN-LIKE AND LITHIUM-LIKE IONS TO HIGHER
C            LEVELS N1,L1 USING CLASSICAL OVERLAPS.
C
C            FOR TRANSITIONS FROM 1S,2S AND 2P APPROXIMATE FITTINGS ARE
C            USED BASED ON SAMPSON DATA.
C
C            FOR TRANSITIONS FROM HIGHER NL LEVELS UPWARDS A RESOLVED
C            VARIANT OF PERCIVAL-RICHARDS IS USED, WITH NUMERICAL
C            QUADRATURES.
C
C  CALLING PROGRAM: ADAS308.
C
C  INPUT : (I*4)  MXNSHL   = MAXIMUM VALUE OF N QUANTUM NUMBER.
C  INPUT : (I*4)  IZ1      = ION CHARGE.OF ION
C  INPUT : (R*8)  IZEFF    = EFFECTIVE ION CHARGE (CF. SAMPSON ET AL.).
C  INPUT : (I*4)  N        = LOWER VALUE OF N QUANTUM NUMBER.
C  INPUT : (I*4)  L        = L QUANTUM NUMBER FOR NL.
C  INPUT : (I*4)  N1       = UPPER VALUE OF N QUANTUM NUMBER.
C  INPUT : (R*8)  TEV      = ELECTRON TEMPERATURE.
C                            UNITS: EV
C
C  OUTPUT: (R*8)  GAMA()   = TABLE OF RATE PARAMETERS.
C                            UNITS:
C                            DIMENSION: REFERENCED BY N QUANTUM NUMBER.
C
C  PARAM : (I*4)  MXN      = 'MXNSHL'.
C  PARAM : (I*4)  NMAX     =
C  PARAM : (R*8)  P1       =
C  PARAM : (R*8)  P2       =
C  PARAM : (R*8)  C1       = 2/3.
C  PARAM : (R*8)  C2       = 4/3.
C
C          (I*4)  L1       = L QUANTUM NUMBER FOR N1.
C          (I*4)  K        =
C          (I*4)  I        = LOOP INDEX.
C          (I*4)  J        = LOOP INDEX.
C
C          (R*8)  Z1       = REAL VALUE = IZ1.
C          (R*8)  ZEFF     = REAL VALUE = IZEFF.
C          (R*8)  Z12      = Z1**2.
C          (R*8)  XN       = REAL VALUE = N.
C          (R*8)  XN1      = REAL VALUE = N1.
C          (R*8)  XND      = REAL VALUE = N1-N.
C          (R*8)  XNP      = REAL VALUE = N1*N.
C          (R*8)  DE       =
C          (R*8)  ATE      =
C          (R*8)  Z2OMT    =
C          (R*8)  SUM      = SUM OF 'FOMA' TERMS.
C          (R*8)  W1       =
C          (R*8)  OVL      =
C          (R*8)  XLN      =
C          (R*8)  XLG      =
C          (R*8)  Z2S      =
C          (R*8)  GAM      =
C          (R*8)  XL       =
C          (R*8)  XM       =
C          (R*8)  XP       =
C          (R*8)  CM       =
C          (R*8)  CP       =
C          (R*8)  D        =
C          (R*8)  E        =
C          (R*8)  F        =
C          (R*8)  G        =
C          (R*8)  H        =
C          (R*8)  T        =
C          (R*8)  Y        =
C
C          (R*8)  XA()     =
C          (R*8)  WA()     =
C          (R*8)  FOMA()   =
C
C          (R*8)  FA(,)    =
C
C ROUTINES:
C          ROUTINE    SOURCE    BRIEF DESCRIPTION
C          -------------------------------------------------------------
C          I4UNIT     ADAS      RETURNS UNIT NO. FOR OUTPUT MESSAGES.
C          CXOVLP     ADAS
C          R8RD2B     ADAS      RETURNS HYDRONIC BOUND-BOUND RADIAL
C                               INTEGRALS.
C          R8FEEI     ADAS
C
C
C AUTHOR:   JONATHAN NASH (TESSELLA SUPPORT SERVICES PLC)
C           K1/0/81
C           JET EXT. 5183
C
C DATE:     05/10/93
C
C VERSION  : 1.2                          
C DATE     : 11-04-2007
C MODIFIED : Allan Whiteford
C               - Renamed R8OVLP to CXOVLP.
C-----------------------------------------------------------------------
C
C-----------------------------------------------------------------------
      INTEGER             IZ1,         IZEFF,       L,           MXNSHL
      INTEGER             N,           N1
      REAL*8              GAMA(MXNSHL),             TEV