SUBROUTINE PFSPEC(IAT,IZI,T,ANE,U,DUT,DUN)
C     ==========================================
 
C     Non-standard evaluation of the partition function
C     user supplied procedure
C
C     Input:
C      IAT   - atomic number
C      IZI   - ionic charge (=1 for neutrals, =1 for once ionized, etc)
C      T     - temperature
C      ANE   - electron density
C      XMAX  - principal quantum number of the last bound level
C
C     Output:
C      U     - partition function
C      DUT   - derivative dU/dT
C      DUN   - derivative dU/d(ANE)
C
      INCLUDE 'IMPLIC.FOR'
C
      U=0.
      DUT=0.
      DUN=0.
      T1=T
      A1=ANE
      IF(IAT.EQ.10) THEN
         IF(IZI.EQ.5) U=9.
         IF(IZI.EQ.6) U=6.
         IF(IZI.EQ.7) U=12.
         IF(IZI.EQ.8) U=8.
         IF(IZI.EQ.9) U=1.
         RETURN
      END IF
      IF(IAT.EQ.16) THEN
         IF(IZI.EQ.5) U=1.
         IF(IZI.EQ.6) U=2.
         IF(IZI.EQ.7) U=1.
         IF(IZI.EQ.8) U=6.
         IF(IZI.EQ.9) U=9.
         RETURN
      END IF

      RETURN
        END