ADAS Subroutine b8corp

C
      SUBROUTINE B8CORP(NLEV   , MAXT   , MAXD   , NMET  ,
     &                  TEVA   , COEFF  )


C-----------------------------------------------------------------------
C
C  ******************* FORTRAN77 SUBROUTINE: B8CORP ********************
C
C  PURPOSE: Corrects unphysical low temperature recombination
C           contributions to a PEC.
C
C           There is a low temperature problem in the production
C           calculation which gives unphysical recombination
C           contributions to the PECs. Generally the first 3-4
C           temperatures in the ADAS 96 standard are affected. This
C           routine replaces the first 4 temperatures from the 
C           recombination contribution with extrapolated values
C           from the remaining data.
C          
C
C  CALLING PROGRAM: ADAS208 (B8WR11)
C
C
C  INPUT : (I*4)  NLEV    = NUMBER OF LEVELS
C  INPUT : (I*4)  MAXT    = NUMBER OF TEMPERATURES
C  INPUT : (I*4)  MAXD    = NUMBER OF DENSITIES
C  INPUT : (I*4)  NMET    = NUMBER OF METASTABLES
C
C  I/O   : (R*4) COEFF()  = RECOMBINATION CONTRIBUTION TO THE PEC 
C                           (STVR IN ADAS208 CALL)
C                           1ST DIMENSION : LEVELS
C                           2ND DIMENSION : TEMPERATURES
C                           3RD DIMENSION : DENSITIES
C                           4TH DIMENSION : METASTABLES
C
C
C ROUTINES:
C          ROUTINE    SOURCE    BRIEF DESCRIPTION
C          ------------------------------------------------------------
C          XXSPLN     ADAS      SPLINE SUBROUTINE 
C          R8FUN1     ADAS      REAL*8 FUNCTION: ( X -> X )
C
C AUTHOR:  Martin O'Mullane
C          
C
C DATE:    14-09-99
C
C
C VERSION: 1.1                          DATE: 14-09-99
C MODIFIED: Martin O'Mullane 
C           - First version
C
C VERSION : 1.2                          
C DATE    : 26-10-99
C MODIFIED: Martin O'Mullane 
C           - Consider each level separately for extrapolation.
C           - Increase NDLEV in line with adas208.
C
C VERSION : 1.3                          
C DATE    : 20-07-07
C MODIFIED: Allan Whiteford
C           - Small modification to comments to allow for automatic
C             documentation preparation.
C
C VERSION : 1.4                          
C DATE    : 02-09-2007
C MODIFIED: Martin O'Mullane
C           - ITAG was defined as real*8 rather than integer.
C
C-----------------------------------------------------------------------
C
C-----------------------------------------------------------------------
      INTEGER             MAXD,        MAXT,        NLEV,        NMET
      REAL                COEFF(NDLEV,NDTEM,NDDEN,NDMET)
      REAL*8              TEVA(NDTEM)