ADAS Subroutine gpcalc

       REAL*8 FUNCTION GPCALC(CFAC1)
       IMPLICIT REAL*8(A-H,O-Z)
C-----------------------------------------------------------------------
C  PURPOSE: ROUTINE TO PROVIDE BURGESS GENERAL PROGRAM RESULTS AT
C  A SERIES OF TEMPERATURES AND AT ZERO DENSITY.
c
C  EQUAL THE GENERAL FORMULA RESULTS AS FAR AS POSSIBLE BY MODIFICATION
C  OF BETHE CORRECTIONS VIA A SINGLE SCALING PARAMETER CORFAC.
C   THE CORRECTION FACTORS USED IN THE GENERAL PROGRAM
C  ARE OBTAINED BY ADJUSTMENT OF STANDARD SETS FOR SPECIFIC TYPES OF
C  TRANSITION.  THE ADJUSTMENT IS
C    (NEW COR(J))=EXP(-CORFAC/(L**DF+0.5))*(STANDARD COR(J)
C  THE STANDARD COR'S ARE AS FOLLOWS:
C   TYPE    TRANSITION                     COR'S                     DF
C     1   NI=1,NJ>=2,LJ=LI+1:       0.05,0.30,0.50,0.90              2.0
C     2   NI=2,NJ=3,LJ=LI+1:        0.01,0.02,0.20,0.40,0.70,0.90    1.0
C     3   NI=2,NJ=3,LJ=LI-1:        0.01,0.01,0.01,0.08,0.30,0.70    1.0
C     4   NJ-NI=0, LJ=LI+1 :        0.30,0.35,0.40,0.45,0.70,0.90    0.5
C     5   NJ-NI=0, LJ=LI-1 :        0.30,0.35,0.40,0.45,0.70,0.90    0.5
C     6   NJ-NI>0, LJ=LI+1 :        0.01,0.02,0.20,0.40,0.70,0.90    1.0
C     7   NJ-NI>0, LJ=LI-1 :        0.01,0.01,0.01,0.08,0.30,0.70    1.0
C
C     (1)  INCLUDE NCUT AND EXTEND ARRAY SIZES
C     (2)  IMPLIMENTATION OF NCUT,LOW TEMPERATURE CHECK, CORRECTION
C          INVOLVING V1
C
C  ********** H.P. SUMMERS, JET             11 JUNE 1987  *************
C  ********** H.P. SUMMERS, JET     MOD.(1) 24 AUG  1989  *************
C  ********** W.J. DICKSON, JET     MOD.(2) 14 DEC  1989  *************
C  INPUT
C      MAXT=NUMBER OF TEMPERATURES
C      TEA(I)=ELECTRON TEMPERATURES (K)
C      Z1=RECOMBINING ION CHARGE
C      N0=LOWEST ACCESSIBLE N-SHELL BY RECOMBINATION
C      V0=EFFECTIVE PRINCIPAL QUANTUM NUMBER OF LOWEST ACCESSIBLE SHELL
C      NI=LOWER PRINCIPAL QUANTUM NUMBER OF PARENT TRANSITION
C      LI=LOWER ANGULAR QUANTUM NUMBER OF PARENT TRNASITION.
C      WI=LOWER PARENT STATE STATISTICAL WEIGHT.
C      NJ=UPPER PRINCIPAL QUANTUM NUMBER OF PARENT TRANSITION
C      LJ=UPPER ANGULAR QUANTUM NUMBER OF PARENT TRNASITION.
C      WJ=UPPER PARENT STATE STATISTICAL WEIGHT.
C      EIJ=PARENT TRANSITION ENERGY (RYD)
C      FIJ=ABSORPTION OSCILLATOR STRENGTH OF PARENT TRANSITION
C      EDISPG=UNIFORM ENERGY DISPLACEMENT FOR GENERAL FORMULA
C      SCALEG=UNIFORM SCALING OF GENERAL FORMULA
C      PHFRAC=INITIAL ESTIMATE OF PHASE SPACE FACTOR
C      CORFAC=INITIAL ESTIMATE OF BETHE CORRECTION SCALER
C      NCUT  =HIGH N CUT-OFF (APPLICABLE TO METASTABLE INITIAL STATES)
C  OUTPUT
C      ALFO(I)=GENERAL PROGRAM DIELECTRONIC COEFFICIENTS (CM+3 SEC-1)
C      PHFRAC=REVISED PHASE SPACE FACTOR
C      CORFAC=REVISED BETHE CORRECTION SCALER
C
C  UPDATE:  07/03/96  HP SUMMERS - INCREASED NRAT FROM 15 TO 100
C
C UNIX-IDL PORT:
C	   WILLIAM OSBORN, TESSELLA SUPPORT SERVICES PLC.
C
C DATE:    19TH APRIL 1996
C
C VERSION: 1.1				DATE: 19-04-96
C MODIFIED: WILLIAM OSBORN
C	    - NRAT WAS 200 FOR SOME REASON : REDUCED TO 100
C
C VERSION: 1.2				DATE: 25-04-96
C MODIFIED: WILLIAM OSBORN
C	    - CHANGED GPCALC TO A FUNCTION FOR USE BY FMIN
C
C VERSION : 1.3
C DATE    : 06-01-2004
C MODIFIED: Martin O'Mullane
C            - Old IBM statement labels in columns 73-80 removed. 
C
C VERSION : 1.4
C DATE    : 16-05-2007
C MODIFIED: Allan Whiteford
C            - Updated comments as part of subroutine documentation
C              procedure.
C
C-----------------------------------------------------------------------
      REAL*8              CFAC1