* test djmm
*
      implicit real*8 (a-h,o-z)                                                       
1     print*,' enter beta (degrees),   j,  m  and  mp'
      read(*,*)beta,rj,rm,rmp
      print*,djmm(beta,rj,rm,rmp)
      goto 1
      stop
      end
*
*=====================================================================
*      
      real*8 function djmm(beta,rj,rm,rmp)                                     
*                                                                       
*  Computes the d-function (lower case D, of beta)
*  beta =  angle in degreses
*  rj = j, rm = m, and rmp = m prime
*
*  Definition in A.R. Edmonds, "Angular Momentum...", Princeton
*  Univ. Press, 1960, eq. 4.1.15
*
*  C.A. Bertulani,  05/13/1995                               
*                
      implicit real*8 (a-h,o-z)                                                       
      real*8 fak(0:130)
      common /gf2 / fak
*
      call GFV(50)
*
      j=2.001*rj                                                        
      m=2.001*rm                                                        
      mp=2.001*rmp                                                      
*      if((j.lt.iabs(m)).or.(j.lt.iabs(mp))) go to 2                     
      b=beta/57.295779                                                  
      cb=cos(b/2.0)                                                     
      sb=sin(b/2.0)                                                     
      ja=(j+mp)/2+1                                                     
      jb=(j-mp)/2+1                                                     
      jc=(j+m)/2+1                                                      
      jd=(j-m)/2+1                                                      
      root=sqrt(fak(ja)*fak(jb)*fak(jc)*fak(jd))                        
      minsig=0                                                          
      if(m+mp.lt.0) minsig=-m-mp                                        
      maxsig=j-m                                                        
      if(m.lt.mp) maxsig=j-mp                                           
      isig=minsig                                                       
      dd=0.0                                                            
   1  ja=isig/2+1                                                       
      jb=(j-m-isig)/2+1                                                 
      jc=(j-mp-isig)/2+1                                                
      jd=(m+mp+isig)/2+1   
      fase=(-1.0)**((j-mp-isig)/2)                                      
      ic=isig+(m+mp)/2                                                  
      is=j-isig-(m+mp)/2                                                
      dd=dd+fase/(fak(ja)*fak(jb)*fak(jc)*fak(jd))*cb**ic*sb**is        
      isig=isig+2                                                       
      if(isig.le.maxsig) go to 1                                        
      djmm=root*dd                                                      
      return                                                            
*2     write(*,3)                                                       
*3     format(24h  error in djmm-argument)                               
*      stop                                                              
      end        
*
*=====================================================================
*      
      subroutine GFV(ie)
*
*  Calculates sign and factorials  of integers and half int.
*
*     iv(n)  =  (-1)**n
*     fak(n) =  n!
*     fad(n) =  n!!
*
      implicit real*8 (a-h,o-z)
      real*8 iv(0:130),fak(0:130),fad(0:130)
      common /gf1 / iv
      common /gf2 / fak
      common /gf3 / fad
*
      if (ie.gt.130) then
       write(12,*) 'STOP IN GFV: IE LARGER 130 '
       stop
      endif
      iv(0)  = +1
      fak(0) =  1.d0
      fad(0)=1.
      fad(1)=1.
      do 10 i=1,ie
         iv(i)  = -iv(i-1)
10       fak(i) = i*fak(i-1)
      do 11 i=3,ie,2
         fad(i) = i*fad(i-2)
11    continue 
      do 12 i=2,ie,2
         fad(i) = i*fad(i-2)
12    continue 
      return
      end
*********************************************************************