ADAS Subroutine bornp2

       SUBROUTINE BORNP2(NMAX,LLOW,LAM,LUP,MLLOW,NU,MLUP,ANS,IOPT)
       IMPLICIT REAL*8(A-H,O-Z)
C-----------------------------------------------------------------------
C  PURPOSE: SECOND STAGE OF BORN X-SECT CALCULATION WITH DIRECTIONAL
C  BEAMS CAUSING TRANSITIONS BETWEEN HYDROGEN STARK/ZEEMAN STATES.
C
C  ANGULAR INTEGRALS OF FORM ???????????????????????????? ARE EVALUATED
C  FOR ALL ORBITAL ANGULAR MOMENTA  0<=L<=NMAX-1
C
C  CALLING ROUTINE WITH IOPT=1 PREPARES LOOKUP TABLES. CALL WITH IOPT=2
C  RETURNS VALUES.
C
C  EVALUATE MULTIPOLES UP TO LAMMX=2
C
C  USE POINTER VECTORS FOR RAPID LOOKUP.
C
C  THE MAIN CALLING ROUTINE MUST HAVE THE LINE
C      CALL GAMAF(200)
C  BEFORE CALL TO BORNP2
C
C  ******** H.P. SUMMERS, JET          17 OCT 1988   *************
C  INPUT
C      NMAX=HIGHEST N-SHELL FOR TABLE PREPARATION
C      LLOW=LOWER L FOR SELECTED TRANSITION
C      LAM=MULTIPOLE (0<=LAM<=LAMMX)
C      LUP=UPPER L FOR SELECTED TRANSITION
C      MLLOW=AZIMUTHAL QUANTUM NUMBER FOR LOWER L
C      NU=MULTIPOLE AZIMUTHAL COMPONENT
C      MLUP=AZIMUTHAL QUANTUM NUMBER FOR UPPER L
C      IOPT=1  PREPARE LOOKUP STACKS (ONLY NMAX PARAMETER USED)
C          =2  SUPPLY ANSWERS FOR SPECIFIED LLOW,LAM,LUP,MLLOW,NU,MLUP
C  OUTPUT
C      ANS(I)=RESULT
C-----------------------------------------------------------------------
C
C ADAS305 version. Developed from JETSHP.STARK.FORT (H P Summers).
C
C VERSION  : 1.1
C DATE     : 24-02-2005
C MODIFIED : Martin O'Mullane
C             - First version.
C             - Change dimensions from 200 to 500.
C
C VERSION  : 1.2
C DATE     : 16-05-2007
C MODIFIED : Allan Whiteford
C             - Updated comments as part of subroutine documentation
C               procedure.
C
C----------------------------------------------------------------------
      INTEGER             IOPT,        LAM,         LLOW,        LUP
      INTEGER             MLLOW,       MLUP,        NMAX,        NU
      REAL*8              ANS