SUBROUTINE DATIN
      IMPLICIT DOUBLE PRECISION (A-H,O-Z)
      INCLUDE 'SIZES'
      CHARACTER NUMBRS(0:9)*1, PARTYP(25)*5, FILES*64, DUMMY*50,
     1          KEYWRD*241, TEXT*50, TXTNEW*50, ELEMNT(107)*2
      COMMON /ATHEAT/ ATHEAT
     1       /MOLKST/ NUMAT,NAT(NUMATM),NFIRST(NUMATM),NMIDLE(NUMATM),
     2                NLAST(NUMATM), NORBS, NELECS,NALPHA,NBETA,
     3                NCLOSE,NOPEN,NDUMY,FRACT
      COMMON /ATOMIC/ EISOL(107),EHEAT(107)
      COMMON /KEYWRD/ KEYWRD
      DIMENSION  IJPARS(5,1000), PARSIJ(1000)
      SAVE NUMBRS, PARTYP, ELEMNT
      DATA NUMBRS/' ','1','2','3','4','5','6','7','8','9'/
      DATA PARTYP/'USS  ','UPP  ','UDD  ','ZS   ','ZP   ','ZD   ',
     1    'BETAS','BETAP','BETAD','GSS  ','GSP  ','GPP  ','GP2  ',
     2    'HSP  ','AM1  ','EXPC ','GAUSS','ALP  ','GSD  ','GPD  ',
     3    'GDD  ','FN1  ','FN2  ','FN3  ','ORB  '/
      DATA (ELEMNT(I),I=1,107)/'H ','HE',
     1 'LI','BE','B ','C ','N ','O ','F ','NE',
     2 'NA','MG','AL','SI','P ','S ','CL','AR',
     3 'K ','CA','SC','TI','V ','CR','MN','FE','CO','NI','CU',
     4 'ZN','GA','GE','AS','SE','BR','KR',
     5 'RB','SR','Y ','ZR','NB','MO','TC','RU','RH','PD','AG',
     6 'CD','IN','SN','SB','TE','I ','XE',
     7 'CS','BA','LA','CE','PR','ND','PM','SM','EU','GD','TB','DY',
     8 'HO','ER','TM','YB','LU','HF','TA','W ','RE','OS','IR','PT',
     9 'AU','HG','TL','PB','BI','PO','AT','RN',
     1 'FR','RA','AC','TH','PA','U ','NP','PU','AM','CM','BK','CF','XX',
     2 'FM','MD','CB','++','+','--','-','TV'/
      I=INDEX(KEYWRD,'EXTERNAL=')+9
      J=INDEX(KEYWRD(I:),' ')+I-1
      FILES=KEYWRD(I:J)
      WRITE(6,'(//5X,'' PARAMETER TYPE      ELEMENT    PARAMETER'')')
      OPEN(14,STATUS='UNKNOWN',FILE=FILES)
      I=0
      NPARAS=0
   10 READ(14,'(A40)',ERR=90,IOSTAT=IOS)TEXT
      NPARAS=NPARAS+1
      IF(TEXT.EQ.' ')GOTO 90
      IF(INDEX(TEXT,'END').NE.0)GOTO 90
      ILOWA = ICHAR('a')
      ILOWZ = ICHAR('z')
      ICAPA = ICHAR('A')
************************************************************************
      DO 20 I=1,50
         ILINE=ICHAR(TEXT(I:I))
         IF(ILINE.GE.ILOWA.AND.ILINE.LE.ILOWZ) THEN
            TEXT(I:I)=CHAR(ILINE+ICAPA-ILOWA)
         ENDIF
   20 CONTINUE
************************************************************************
      IF(INDEX(TEXT,'END') .NE. 0) GOTO 90
      DO 30 J=1,25
         IF(J.GT.21) THEN
            IT=INDEX(TEXT,'FN')
            TXTNEW = TEXT(1:IT+2)
            IF(INDEX(TXTNEW,PARTYP(J)) .NE. 0) GOTO 40
         ENDIF
         IF(INDEX(TEXT,PARTYP(J)) .NE. 0) GOTO 40
   30 CONTINUE
      WRITE(6,'(''  FAULTY LINE:'',A)')TXTNEW
      WRITE(6,'(''  FAULTY LINE:'',A)')TEXT
      WRITE(6,'(''   NAME NOT FOUND'')')
      STOP
   40 IPARAM=J
      IF(IPARAM.GT.21) THEN
         I=INDEX(TEXT,'FN')
         KFN=READA(TEXT,I+3)
      ELSE
         KFN=0
         I=INDEX(TEXT,PARTYP(J))
      ENDIF
      K=INDEX(TEXT(I:),' ')+1
      DUMMY=TEXT(K:)
      TEXT=DUMMY
      DO 50 J=1,107
   50 IF(INDEX(TEXT,' '//ELEMNT(J)) .NE. 0) GOTO 60
      WRITE(6,'('' ELEMENT NOT FOUND '')')
      WRITE(6,*)' FAULTY LINE: "'//TEXT//'"'
      STOP
   60 IELMNT=J
      PARAM=READA(TEXT,INDEX(TEXT,ELEMNT(J)))
      DO 70 I=1,LPARS
         IF(IJPARS(1,I).EQ.KFN.AND.IJPARS(2,I).EQ.IELMNT.AND.
     1IJPARS(3,I).EQ.IPARAM) GOTO 80
   70 CONTINUE
      LPARS=LPARS+1
      I=LPARS
   80 IJPARS(1,I)=KFN
      IJPARS(2,I)=IELMNT
      IJPARS(3,I)=IPARAM
      PARSIJ(I)=PARAM
      GOTO 10
   90 CONTINUE
      IF(NPARAS.EQ.0)THEN
         WRITE(6,'(//10X,A)')' EXTERNAL PARAMETERS FILE MISSING OR EMPTY
     1'
         STOP
      ENDIF
      CLOSE(14)
      DO 120 J=1,107
         DO 110 K=1,25
            DO 100 I=1,LPARS
               IPARAM=IJPARS(3,I)
               KFN=IJPARS(1,I)
               IELMNT=IJPARS(2,I)
               IF(IPARAM.NE.K) GOTO 100
               IF(IELMNT.NE.J) GOTO 100
               PARAM=PARSIJ(I)
               IF(KFN.NE.0)THEN
                  WRITE(6,'(10X,A6,11X,A2,F17.6)')
     1PARTYP(IPARAM)(:3)//NUMBRS(KFN)//'  ',
     2ELEMNT(IELMNT),PARAM
               ELSE
                  WRITE(6,'(10X,A6,11X,A2,F17.6)')
     1PARTYP(IPARAM)//NUMBRS(KFN),
     2ELEMNT(IELMNT),PARAM
               ENDIF
               CALL UPDATE(IPARAM,IELMNT,PARAM,1,KFN)
  100       CONTINUE
  110    CONTINUE
  120 CONTINUE
      CALL MOLDAT(1)
      CALL CALPAR
      ATHEAT=0.D0
      ETH=0.D0
      DO 130 I=1,NUMAT
         NI=NAT(I)
         ATHEAT=ATHEAT+EHEAT(NI)
  130 ETH=ETH+EISOL(NI)
      ATHEAT=ATHEAT-ETH*23.061D0
      RETURN
      END