ADAS Subroutine i4lgrp

      FUNCTION I4LGRP(CHR)
C---------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: I4LGRP *******************
C
C  PURPOSE: RETURNS ANGULAR MOMENTUM QUANTUN NUMBER OF ORBITAL 
C           GIVEN IN THE EISSNER SINGLE HEXADECIMAL CHARACTER FORM
C
C  CALLING PROGRAMS: GENERAL USE
C
C  SUBROUTINE:
C
C  INPUT :(C*1)  CHR     = HEX. ORBITAL CHARACTER (EG. 'A')
C
C  OUTPUT:(I*4)  I4LGRP  = DECIMAL ORBITAL CHARACTER (E.G. '0')
C
C  AUTHOR:  W.J.DICKSON  
C
C  DATE:    20/10/89
C
C  UPDATE:  19/02/03  H.P. SUMMERS - EXTENDED RANGE
C 
C
C UNIX-IDL PORT:
C	   WILLIAM OSBORN, TESSELLA SUPPORT SERVICES PLC.
C
C DATE:    22ND APRIL 1996
C
C VERSION: 1.1				DATE: 22-04-96
C MODIFIED: WILLIAM OSBORN
C	    - FIRST VERSION. NO CHANGES TO IBM CODE.
C
C VERSION: 1.2				DATE: 19/02/03
C MODIFIED: H.P. SUMMERS 
C		- EXTENDED RANGE
C
C-----------------------------------------------------------------------
      CHARACTER           CHR