!-----------------------------------------------------!
!                                                     !
! A SIMPLE PROG TO CONVERT VTF TRAJECTORY INTO LAMMPS !
! Dusan Racko (c) 2011								  !
!                                                     !
!-----------------------------------------------------!
PROGRAM VTF
CHARACTER*80  :: ARG, FILEIN, FILEOUT
CHARACTER*256 :: XLINE, XWORD, PRINTL
INTEGER :: STAT
INTEGER :: POS1, POS2, n
INTEGER :: NAT, NSTEPS, ID
CHARACTER*14 :: PBC (1:3)
INTEGER :: CT_PBC
!defaults
CT_PBC = 0	!#CONTROL: PERIODIC SYSTEM?
NSTEPS = 0
STAT = -1
!---

 !#READ FILENAME FROM COMMANDLINE IF ENTERED
 CALL GETARG (1, ARG, STAT) 

 IF (STAT.EQ.-1) THEN
  WRITE (0,*) 'NAME OF A FILE TO BE CONVERTED: '
  READ (*,*) FILEIN
 ELSE
  FILEIN = TRIM(ADJUSTL(ARG))
 END IF

 POS1 = INDEX (FILEIN,'.')
 WRITE (FILEOUT,*) TRIM (ADJUSTL(FILEIN(1:POS1-1))),'.lammpstrj'

 OPEN (7, FILE = FILEIN)

!#GET GLOBAL PARAMETERS: NSTEP, NAT
  DO WHILE (.NOT.EOF(7))

   READ (7, '(A256)') XLINE
    
	!#GET PBC
	IF (TRIM (XLINE(1:1)).EQ.'p') THEN
	 CT_PBC = 1
	 n = 0
	 POS1 = 1
     POS2 = INDEX (XLINE(POS1:), ' ')
      DO WHILE (n.LE.20)
	   POS2 = INDEX (XLINE(POS1:), ' ')
	   XWORD = TRIM (ADJUSTL(XLINE(POS1:POS1+POS2-2)))
	    IF ((LEN(TRIM(XWORD)).GT.1).AND.(N.GE.1)) THEN 
		 WRITE (PBC(N),*) TRIM(ADJUSTL(XWORD))
		END IF
	   POS1 = POS1 + POS2
	   n = n + 1
 	  END DO
	END IF

	!#GET ATOMIC COORDS
    IF (TRIM (XLINE(1:1)).EQ.'t') THEN

	 NSTEPS = NSTEPS + 1
	 NAT = 0
	 READ (7, '(A256)') XLINE

	 CHARID = 45
	 DO WHILE ((CHARID.GE.45).AND.(CHARID.LE.57))
	  NAT = NAT + 1
	  READ (7, '(A256)') XLINE
	  CHARID = ICHAR (XLINE(1:1))
	 END DO

	END IF

  END DO

 CLOSE (7)

!# GLOBAL PARAMS INFO ON SCREEN 
 WRITE (0,'(A35,I6,A11)') 'THE CONVERTED TRAJECTORY CONTAINS ', NSTEPS,' STRUCTURES.'
 WRITE (0,'(A33,I6,A8 )') 'EACH OF THE STRUCTURES CONTAINS ', NAT,' ATOMS.'
 IF (CT_PBC) WRITE (0,*) 'PERIODIC BOUNDARY DETECTED: ', TRIM(PBC(1)),' ', TRIM(PBC(2)),' ',TRIM(PBC(3))
 WRITE (0,*) 'OUTPUT FILE: ', TRIM(ADJUSTL(FILEOUT))
 WRITE (0,*)
 WRITE (0,*) 'CONVERTING..'

!#CONVERT TO LAMMPSTRJ
 OPEN (7, FILE = FILEIN)
 OPEN (8, FILE = FILEOUT)

  NSTEPS = 0
  DO WHILE (.NOT.EOF(7))

   READ (7, '(A256)') XLINE

    IF (TRIM (XLINE(1:1)).EQ.'t') THEN

	 NSTEPS = NSTEPS + 1

 	 WRITE (8,'(A14)')	'ITEM: TIMESTEP'
	 WRITE (8,*) NSTEPS
	 WRITE (8,'(A21)')	'ITEM: NUMBER OF ATOMS'
	 WRITE (8,*) NAT
	 WRITE (8,'(A16)')	'ITEM: BOX BOUNDS'
	 WRITE (8,*) '0 ', TRIM(PBC(1))
	 WRITE (8,*) '0 ', TRIM(PBC(2))
	 WRITE (8,*) '0 ', TRIM(PBC(3))
	 WRITE (8,'(A11)')	'ITEM: ATOMS'

	 ID = 0
	 !READ (7, '(A256)') XLINE

	 CHARID = 45
	 DO WHILE ((CHARID.GE.45).AND.(CHARID.LE.57))
	  ID = ID + 1
	  READ (7, '(A256)') XLINE
	  WRITE (PRINTL,*) ID,' 1 ',TRIM(ADJUSTL(XLINE))
 	   IF (ID.LE.NAT) WRITE (8,*) TRIM(ADJUSTL(PRINTL))
	  CHARID = ICHAR (XLINE(1:1))
	 END DO

	END IF

  END DO

 CLOSE (8)
 CLOSE (7)

END PROGRAM

!