DICVOL06

   ==========================================================================
   ==========================================================================

   DDDDDDD   IIII   CCCCCC   VV    VV   OOOOOO   LL          0000        66
   DD    DD   II   CC    CC  VV    VV  OO    OO  LL         00  00      66
   DD    DD   II   CC        VV    VV  OO    OO  LL        00    00    66
   DD    DD   II   CC        VV    VV  OO    OO  LL        00    00   66  66
   DD    DD   II   CC         VV  VV   OO    OO  LL        00    00   66   66
   DD    DD   II   CC    CC    VVVV    OO    OO  LL    LL   00  00    66   66
   DDDDDDD   IIII   CCCCCC      VV      OOOOOO   LLLLLLLL    0000      66666

   ==========================================================================
   ==========================================================================

      TWO OPTIONS ARE AVAILABLE WITH DICVOL06
      ---------------------------------------

  >> OPTION 0 IS DICVOL04 (OPTIMISED SEARCH TO BE USED WITH NORMAL QUALITY
     DATA)

  >> OPTION 1 OFFERS AN EXTENDED (EXHAUSTIVE) SEARCH (FOR DIFFICULT CASES)

   [COMPARED TO DICVOL04 (2004) ONLY ONE ADDITIONAL INPUT PARAMETER IS ADDED
   IN DICVOL06, i.e. OPTION IN CARD 5 (SEE BELOW)]

         --------------------------------------------------------------
         --------------------------------------------------------------
         --------------------------------------------------------------
         |    TO EXECUTE THE PROGRAM, ENTER :      DICVOL06           | 
         |                                                            |
         |    THEN, ENTER THE INPUT FILE NAME and OUTPUT FILE NAME    |
         --------------------------------------------------------------
         --------------------------------------------------------------
         --------------------------------------------------------------

      PROGRAM FOR THE AUTOMATIC INDEXING OF POWDER DIFFRACTION PATTERNS BY
      THE SUCCESSIVE DICHOTOMY METHOD.

      ------------------------------------------------------------------
  >>>>    THE REFERENCE FOR THIS PROGRAM, TO REPORT IN PUBLICATIONS, IS:

  >>>>    (1): A. Boultif & D. Louer, J. Appl. Cryst. 37, 724-731, 2004
      ------------------------------------------------------------------

      THE FOLLOWING CRYSTAL SYSTEMS CAN BE ANALYZED: CUBIC, TETRAGONAL,
      HEXAGONAL, ORTHORHOMBIC, MONOCLINIC AND TRICLINIC.

      PRECURSOR PROGRAMS:
      P1 & P2 (REF. 2), DICVOL (REF. 3), DICVOL91 (REF. 4), DICVOL04 (REF. 1)

                                   =======================

      FOR FURTHER INFORMATION CONTACT
                D. LOUER
                E-MAIL  Daniel.Louer@free.fr

          OR
                A. BOULTIF
                LABORATOIRE DE CRISTALLOGRAPHIE
                DEPARTEMENT DE PHYSIQUE
                FACULTE DES SCIENCES EXACTES
                UNIVERSITE MENTOURI - CONSTANTINE
                25000 CONSTANTINE - ALGERIE
                TEL./FAX  (213) 31 61 47 47
                E-MAIL  ABoultif@ifrance.com

       ---------------------------------------------------------------
       |            G E N E R A L   I N S T R U C T I O N S          |
       ---------------------------------------------------------------

       DICVOL PROPOSES SOLUTIONS; THE USER DISPOSES OF THEM.
       THE AUTHORS DISCLAIM RESPONSABILITY FOR ALL USE OF THIS PROGRAM
       ---------------------------------------------------------------

  ===> BEFORE USING DICVOL06, PLEASE READ REFERENCE 1, AS WELL AS THE
  ===> INSTRUCTIONS AND RECOMMENDATIONS BELOW.

       _______________
       INPUT DATA FILE
       ---------------

   CARD 1  TITLE                                          FREE FORMAT


   CARD 2  N,ITYPE,JC,JT,JH,JO,JM,JTR                     FREE FORMAT

           N               NUMBER OF LINES USED FOR SEARCHING SOLUTIONS.
                           (This number is, generally, lower than the
                           number N_TOTAL of input lines). e.g. N = 20.
           ITYPE           SPACING DATA TYPE.
                       =1  THETA BRAGG ANGLE IN DEGREES.
                       =2  2-THETA ANGLE IN DEGREES.
                       =3  D-SPACING IN ANGSTROM UNIT.
                       =4  Q SPECIFIED IN Q-UNITS AS E+04/D**2.
           JC          =0  CUBIC SYSTEM IS NOT TESTED.
                       =1  CUBIC SYSTEM IS TESTED.
           JT          =0  TETRAGONAL SYSTEM IS NOT TESTED.
                       =1  TETRAGONAL SYSTEM IS TESTED.
           JH          =0  HEXAGONAL SYSTEM IS NOT TESTED.
                       =1  HEXAGONAL SYSTEM IS TESTED.
           JO          =0  ORTHORHOMBIC SYSTEM IS NOT TESTED.
                       =1  ORTHORHOMBIC SYSTEM IS TESTED.
           JM          =0  MONOCLINIC SYSTEM IS NOT TESTED.
                       =1  MONOCLINIC SYSTEM IS TESTED.
           JTR         =0  TRICLINIC SYSTEM IS NOT TESTED.
                       =1  TRICLINIC SYSTEM IS TESTED.


   CARD 3  AMAX,BMAX,CMAX,VOLMIN,VOLMAX,BEMIN,BEMAX       FREE FORMAT

           AMAX    MAXIMUM VALUE OF UNIT CELL DIMENSION A, IN ANGSTROMS.
                   (IF AMAX= 0.0 DEFAULT= 25. ANGSTROMS)
           BMAX    MAXIMUM VALUE OF UNIT CELL DIMENSION B, IN ANGSTROMS.
                   (IF BMAX= 0.0 DEFAULT= 25. ANGSTROMS)
           CMAX    MAXIMUM VALUE OF UNIT CELL DIMENSION C, IN ANGSTROMS.
                   (IF CMAX= 0.0 DEFAULT= 25. ANGSTROMS)
           VOLMIN  MINIMUM VOLUME FOR UNIT CELLS IN ANGSTROMS**3.
           VOLMAX  MAXIMUM VOLUME FOR UNIT CELLS IN ANGSTROMS**3.
                   (IF VOLMAX= 0.0 DEFAULT= 2500. ANGSTROMS**3)
           BEMIN   MINIMUM BETA ANGLE FOR MONOCLINIC CELLS IN DEGREES
                   (IF BEMIN= 0.0 DEFAULT= 90. DEGREES).
           BEMAX   MAXIMUM BETA ANGLE FOR MONOCLINIC CELLS IN DEGREES
                   (IF BEMAX= 0.0 DEFAULT= 125. DEGREES).


   CARD 4  WAVE,POIMOL,DENS,DELDEN                        FREE FORMAT

           WAVE    WAVELENGTH IN ANGSTROMS (DEFAULT=0.0 IF CU K ALPHA1).
           POIMOL  MOLECULAR WEIGHT OF ONE FORMULA UNIT IN A.M.U.
                   (DEFAULT =0.0 IF FORMULA WEIGHT NOT KNOWN).
           DENS    MEASURED DENSITY IN G CM(**-3)
                   (DEFAULT =0.0 IF DENSITY NOT KNOWN).
           DELDEN  ABSOLUTE ERROR IN MEASURED DENSITY.
                   (DEFAULT =0.0 IF DENSITY NOT KNOWN).


   CARD 5  EPS,FOM,N_IMP,ZERO_S,ZERO_REF,OPTION           FREE FORMAT

           EPS       =0.0  THE ABSOLUTE ERROR ON EACH OBSERVED LINE
                           IS TAKEN TO 0.03 DEG. 2THETA (DEFAULT VALUE)
                           WHATEVER THE SPACING DATA TYPE (ITYPE IN CARD 2).
                     =1.0  THE ABSOLUTE ERROR ON EACH OBSERVED LINE IS
                           INPUT INDIVIDUALLY FROM CARD 6, AFTER THE
                           OBSERVED 'D(I)' ON THE SAME LINE, ACCORDING
                           TO THE SPACING DATA UNIT (e.g.  18.678 0.018 in
                           deg. 2theta)
                     EPS NE 0.0 AND 1.0
                           THE ABSOLUTE ERROR IS TAKEN AS A CONSTANT
                           (= EPS),IN DEG. 2THETA, WHATEVER THE SPACING
                           DATA TYPE (ITYPE IN CARD 2) (e.g. 0.02, which will
                           apply to all input lines).
           FOM             LOWER FIGURE OF MERIT M(N) REQUIRED FOR PRINTED
                           SOLUTION(S) (DEFAULT=0.0  M(N)=10.0).
           N_IMP     MAXIMUM NUMBER OF IMPURITY/SPURIOUS LINES ACCEPTED AMONG
                           THE FIRST N LINES [N_IMP takes into account both
                           impurity lines and peak positions out of the input
                           absolute angular error EPS].
                     IF N_IMP <0  THE SEARCH STARTS WITH ZERO IMPURITY LINES,
                           THEN, IT CONTINUES WITH ONE IMPURITY LINE, AND
                           SO ON UNTIL 'N_IMP' IMPURITY LINES IS REACHED.
           ZERO_S    A PRIORI SEARCH FOR A ZERO-POINT ERROR IN INPUT DATA.
                     =0    NO SEARCH
                     =1    SEARCH
                     IF ZERO_S NE 0 OR 1, THEN ZERO_S REPRESENTS A KNOWN
                           ZERO CORRECTION (e.g. -0.10) IN DEG. 2THETA.
           ZERO_REF  =0    NO 'ZERO-POINT' LEAST-SQUARES REFINEMENT.
                     =1    'ZERO-POINT' LEAST-SQUARES REFINEMENT.

           OPTION    =0    DICVOL04 OPTION (OPTIMIZED STRATEGY SEARCH WITH
                           DECREASING CELL VOLUMES).
                     =1    OPTION WITH EXTENDED (EXHAUSTIVE) SEARCH IN VOLUME
                           DOMAINS CONTAINING MATHEMATICAL SOLUTION(S)
                           (LONGER CPU TIMES).
                     IF OPTION IS OMITTED, DEFAULT IS DICVOL04.

   CARDS 6 to 6+N_TOTAL   D(I) [,EPSIL(I)]                FREE FORMAT

           (ONE FOR EACH INPUT LINE, FOR ALL N_TOTAL LINES)
           D(I)     VALUE DESCRIBING THE OBSERVED POSITION OF LINE 'I'
                    ACCORDING TO SPACING UNIT 'ITYPE'.
           EPSIL(I) ONLY IF EPS=1.0 (CARD 5): ABSOLUTE ERROR FOR 'D(I)',
                    ACCORDING TO 'ITYPE', 
                    [IF EPS= 0.0 OR EPS IS A CONSTANT NOT EQUAL TO 1.0 (e.g.
                    0.02)(SEE CARD 5), ONLY 'D(I)' ARE REQUIRED].
   NOTE:
           IF ITYPE=1,2,4 THE VALUES OF 'D(I)' AND 'EPSIL(I)' MUST
           BE PREFERABLY (THOUGH IT IS NOT MANDATORY) LISTED IN INCREASING
           ORDER.
           IF ITYPE=3 THEY MUST BE PREFERABLY LISTED IN DECREASING ORDER.

       ___________
       OUPUT FILES
       -----------

  DICVOL06 GENERATES TWO OUTPUT FILES:

           - A FILE CONTAINING THE SOLUTIONS AS FOUND BY THE PROGRAM (ALSO
             SEEN ON THE DISPLAY WHEN DICVOL06 IS RUNNING).
           - A SECOND FILE WITH THE SAME NAME AND THE EXTENSION '.ord', IN
           WHICH ALL (MATHEMATICAL) SOLUTIONS ARE RANKED ACCORDING TO THEIR
           de WOLFF FOM.

         *****************************************************
         *                                                   *
         *               THE USE OF DICVOL06                 *
         *                                                   *
         *****************************************************

       USE AS INPUT DATA ALL AVAILABLE DIFFRACTION LINES (N_TOTAL). ONLY THE
       FIRST N (eg 20, SEE CARD 2) LINES WILL BE USED FOR THE SEARCH OF
       SOLUTIONS. THESE SOLUTIONS ARE SUBSEQUENTLY USED AUTOMATICALLY FOR
       REVIEWING ALL N_TOTAL INPUT DATA. THE IMPURITY TOLERANCE 'N_IMP' IS
       RELATED ONLY TO THE N LINES USED FOR SEARCHING SOLUTION(S) (OF COURSE,
       OTHER UNINDEXED LINES CAN BE FOUND AMONG THE EXTRA INPUT LINES IN THE
       REVIEWING PROCESS). BE CAREFUL IN USING THE IMPURITY TOLERANCE:
       SPURIOUS LINES INCREASES THE RISK TO MISS THE CORRECT SOLUTION!

       ==> WITH GOOD QUALITY DATA, OPTION = 0 (i.e. DICVOL04) IS RECOMMENDED.

       ==>THE OPTION 'EXTENDED (EXHAUSTIVE) SEARCH'  (OPTION =1 IN CARD 5),
       CAN BE USEFUL IN CASES OF
        (i) UNSTABLE CASES, i.e. MANY SOLUTIONS ARE FOUND IN A SMALL RANGE OF
        CELL VOLUMES,
        (ii) EXPECTED DIFFRACTION LINES ARE MISSING AMONG THE FIRST INPUT
        LINES,
        (iii) LOW QUALITY DATA,
        (iv) SIGNIFICANT NUMBER OF IMPURITY LINES, ETC.
       IF A SOLUTION IS FOUND IN A VOLUME SHELL, THE SEARCH IS EXHAUSTIVE
       WITHIN THIS SHELL. THUS, THE SEARCH IS NOT EXTENDED TO THE NEXT VOLUME
       SHELL (FOR THE SYMMETRY BEING ANALYSED). IF NEEDED, THE USER CAN RUN
       AGAIN DICVOL06, FOR SELECTED LATTICE SYSTEMS, TAKING THE HIGHER VOLUME
       VALUE OF THE ALREADY ANALYSED VOLUME SHELL AS 'VOLMIN' IN THE NEW INPUT
       PARAMETERS SET (CARD 3).

       GENERALLY, RUNS WITH OPTION =1 TAKE LONGER CPU TIMES AND THE NUMBER OF
       MATHEMATICAL SOLUTIONS IS GREATER (IT HAS BEEN LIMITED TO THE FIRST 100
       FOUND SOLUTIONS IN THE DICVOL06 OUTPUT FILE). BY ACTING ON THE INPUT
       FOM (GREATER FOM IN CARD 5) SOLUTIONS WITH LOWEST FOMs CAN BE REJECTED).
       BE CAREFUL: AS SOON AS 100 SOLUTIONS ARE FOUND THE CALCULATION STOPS.

       DICVOL06 OFFERS THE POSSIBILITY TO ANALYSE YOUR INPUT DATA FOR THE
       PRESENCE OF A ZERO-POINT ERROR. THE METHOD EMPLOYED CAN SUGGEST MORE
       THAN ONE OR TWO SOLUTIONS (DUE TO UNCERTAINTY IN SEARCHING HARMONIC
       DIFFRACTION LINES). THIS OPTION IS TO BE USED PRIOR THE INDEXING
       PROCESS. PLEASE, AS FAR AS POSSIBLE AVOID THE USE OF THIS FACILITY BY
       ENSURING THE QUALITY OF YOUR COLLECTED DATA!

       USUAL 'ZERO-POINT' ERRORS (IF NOT TOO BIG) ARE GENERALLY CORRECTED BY
       THE LEAST-SQUARES REFINEMENT OF THE 'ZERO-POINT' PARAMETER (ZERO_REF IN
       CARD 5), TOGETHER WITH THE REFINEMENT OF CELL PARAMETERS. ZERO_REF IN
       CARD 5 IS, IN FACT, AN EXTRA DEGREE OF FREEDOM IN THE REFINEMENT. IT
       INCLUDES ALL SYSTEMATIC MEASUREMENT ERRORS FROM DIFFRERENT ORIGIN,
       E.G. ZERO-POINT SHIFT, SAMPLE-SURFACE DISPLACEMENT, UMBRELLA EFFECT,
       TRANSPARENCY, CAPILLARY DISPLACEMENT, ..

       SUGGESTED STRATEGY:
       ------------------
       IT IS RECOMMENDED TO USE A TWO- [1 & 2] OR THREE-STAGES PROCEDURE
       (i.e. TRICLINIC LATTICES SHOULD PREFERABLY BE STUDIED SEPARATELY), e.g.:
         1- SEARCH IN HIGH SYMMETRIES DOWN TO ORTHORHOMBIC.
            CARD 2 : N,ITYPE,1,1,1,1,0,0
         2- SEARCH IN MONOCLINIC SYMMETRY.
            CARD 2 : N,ITYPE,0,0,0,0,1,0
         3- IF NECESSARY, SEARCH IN TRICLINIC SYMMETRY.
            CARD 2 : N,ITYPE,0,0,0,0,0,1

       NOTE THAT FOR SOLUTIONS WITH MONOCLINIC AND TRICLINIC SYMMETRIES
       THE PROGRAM PROVIDES THE REDUCED CELL. IF VARIOUS EQUIVALENT SOLUTIONS
       ARE FOUND, ONLY ONE OF THEM IS LISTED IN THE OUTPUT FILE.

       TRIGONAL SYMMETRY CASE WITH RHOMBOHEDRAL LATTICE: THE PATTERN IS
       INDEXED WITH AN HEXAGONAL LATTICE, HAVING A UNIT CELL VOLUME THREE
       TIMES GREATER.

   RECOMMENDATIONS
   ---------------
       READ CAREFULLY REFERENCES 1 AND 6 (AND 9), AS WELL AS THIS USER'S
       GUIDE. PLEASE, SPEND TIME TO ENSURE THE QUALITY OF YOUR COLLECTED DATA
       (SEE REF. 5). WITH ACCURATE DATA, THE SUCCESS RATE OF DICVOL06 IS VERY
       HIGH. PEAK POSITIONS SHOULD BE EXTRACTED WITH A PROFILE FITTING
       SOFTWARE. AN INTERACTIVE PROGRAM SHOULD BE PREFERRED, SINCE AUTOMATIC
       EXTRACTIONS CAN MISS LINES (LOW INTENSITY, SHOULDER, ..).

       WITH BAD DATA, THE CHANCE TO OBTAIN THE CORRECT SOLUTION IS SMALL AND
       THE CALCULATION CAN BE TIME-CONSUMING.

       WITH MODERN X-RAY POWDER DIFFRACTOMETERS (THE USE OF MONOCHROMATIC
       RADIATION IS RECOMMENDED), ABSOLUTE ERRORS ON PEAK POSITIONS LOWER
       THAN 0.02 DEGREES 2-THETA CAN BE ROUTINELY OBTAINED. FOR INDEXING
       PURPOSES, ERRORS SHOULD NOT (IDEALLY) EXCEED 0.03 DEG. 2-THETA.
       [IN EXCEPTIONAL CASES, A FEW LINES WITH GREATER INDIVIDUAL ESTIMATED
       ERROR CAN BE INTRODUCED IN THE INPUT DATA. IN THIS CASE, USE THE
       PARAMETER EPS= 1. IN CARD 5, AND ENTER INDIVIDUAL ERRORS AFTER D(I) FOR
       EACH LINE].

       WITH HIGH RESOLUTION POWDER DIFFRACTION DATA (CONVENTIONAL OR,
       PARTICULARLY, SYNCHROTRON X-RAY SOURCES), THE ABSOLUTE ERROR IS
       USUALLY LESS THAN 0.02 (OR EVEN 0.01 WITH ULTRA-HIGH RESOLUTION) DEG.
       2-THETA; CONSEQUENTLY, EPS=0.02 (OR EVEN EPS=0.01) IS RECOMMENDED; THE
       CONVERGENCE OF THE DICHOTOMY PROCEDURE WILL BE IMPROVED. HOWEVER, BE
       SURE THAT THIS CONDITION IS TRUE FOR ALL LINES USED AS INPUT DATA.
       (REMEMBER THAT ALL MATHEMATICAL SOLUTIONS WITHIN THE INPUT LIMITS AND
       ERROR BOUNDS ARE FOUND, THE GREATER THEY ARE THE GREATER IS THE NUMBER
       OF MATHEMATICAL SOLUTIONS).

       ===> N_IMP PARAMETER: N_IMP CAN BE USED IN CASE OF EXPECTED SPURIOUS
       LINES (i.e. IMPURITY LINES, AS WELL AS OBSERVED LINES OUT OF THE INPUT
       ERROR). N_IMP ACTS AT ALL SUCCESSIVE LEVELS OF THE DICHOTOMY ALGORITHM.
       AS SOON AS AN INDEXING SOLUTION IS RETAINED, A LEAST-SQUARES REFINEMENT
       OF LATTICE PARAMETERS IS CARRIED OUT. FOR THIS REFINEMENT A LARGER
       ERROR ON OBSERVED LINES IS CONSIDERED. THEN, A LINE REJECTED AT THE
       LAST DICHOTOMY LEVEL CAN, BY CHANCE, BE ACCEPTED WITH THE REFINED
       LATTICE PARAMETERS. [EXAMPLE OF POSSIBLE CASE: N_IMP = 0  NO SOLUTION;
       N_IMP = 1 ONE SOLUTION; HOWEVER, AFTER L-S REFINEMENT OF THE LATTICE
       PARAMETERS ALL N LINES USED FOR SEARCHING SOLUTIONS ARE INDEXED WITH
       THE REFINED PARAMETERS.]

       NOTE THAT THE PROGRAM DICVOL06 IS EXECUTABLE FROM 7 LINES- 8 LINES IF
       THE 'ZERO-SHIFT' IS REFINED - (THOUGH IT IS NOT RECOMMENDABLE SINCE L-S
       REFINEMENT UNSTABILITIES CAN BE EXPECTED).

       LONG AND SHORT AXIS CASES (DOMINANT ZONE CASES): IF SUCH CASES ARE
       EXPECTED, THE NUMBER 'N' OF LINES (CARD 2) USED FOR SEARCHING THE
       SOLUTION SHOULD, GENERALLY, BE GREATER THAN 20.

       THE MINIMUM VALUE FOR A LINEAR LATTICE PARAMETER HAS BEEN FIXED TO 2.5
       ANGSTROMS.

       RELIABILITY OF INDEXING SOLUTIONS: READ PARAGRAPH 8 OF REF. 5 AND
       REFS 7 AND 8.

       THE BEHAVIOUR OF THE DICHOTOMY ALGORITHM WITH RESPECT TO THE NUMBER OF
       LINES REQUIRED FOR INDEXING AND THE CASE OF BIPHASIC MIXTURE IS
       DISCUSSED IN REF. 6.

       THE LOGICAL FILTERS USED IN DICVOL06 FOR THE SELECTION OF SOLUTIONS
       ARE DESCRIBED IN REF. 9.

       NOTE THAT WITH THE OPTION DICVOL04 (OPTION =0), AS SOON AS A SOLUTION
       IS FOUND, ONLY SOLUTIONS WITH SMALLEST VOLUMES WILL BE SUBSEQUENTLY
       RETAINED. IF (FOR SOME REASONS!) YOU ARE NOT SATISFIED BY THE SOLUTION,
       YOU CAN RUN AGAIN THE PROGRAM WITH AN INPUT LOWER VOLUME LIMIT SLIGHTLY
       GREATER THAN THAT OF THE FOUND SOLUTION (THE EXHAUSTIVE SEARCH IS THEN
       EXTENDED TO A HIGHER VOLUME).

       NOTE THAT THE SEARCH IS EXHAUSTIVE WITHIN THE LIMITS ON THE INPUT DATA. 
       IN PARTICULAR, THE SEARCH IS CONSTRAINED BY THE HIGHER AND SMALLER
       BOUNDS ON PARAMETERS, VOLUMES, SELECTED FOM AND ABSOLUTE ERRORS ON PEAK
       POSITIONS. PLEASE ACT ON THESE PARAMETERS WHEN USING DICVOL06.

       A LATTICE METRIC SINGULARITY OCCURS WHEN UNIT CELLS DEFINING TWO 
       LATTICES HAVE AN IDENTICAL SET OF CALCULATED d-SPACINGS. THIS CAN
       BE OBSERVED WITH HIGH SYMMETRY LATTICES (READ REF.5, SECT. 4.2, AND
       REFS THEREIN). SIMPLE RELATIONS EXIST BETWEEN THE PARAMETERS OF THE TWO
       CELLS, AS WELL AS PARTICULAR CELL-VOLUME RATIOS. A TYPICAL CASE IS: AN
       HEXAGONAL CELL [a, c, VOLUME V] CAN BE INDEXED WITH AN ORTHORHOMBIC
       CELL [PARAMETERS: a/2, a SQRT(3), c, VOLUME V/2]. DUE TO THE STRATEGY
       USED IN DICVOL, BASED ON AN ANALYSIS THROUGH DECREASING SYMMETRY, ALL
       CELLS SHOULD BE, IN PRINCIPLE, DISPLAYED IN THE OUTPUT FILE (EXCEPT IF
       A SOLUTION IS REJECTED BY THE INPUT MAXIMUM VOLUME).

       CHECK ON VALIDITY OF AN INDEXING RESULT: PLEASE READ REF. 5 (SECT. 8)

       POSSIBLE SPACE GROUPS: LOOK AT THE HKL CONDITIONS IN THE OUTPUT
       LIST OF THE REVIEWING OF THE COMPLETE INPUT DATA PROVIDED AFTER A
       SOLUTION IS FOUND FROM THE FIRST N LINES.

       ADDITIONAL INFORMATION ON DICVOL06 SHOULD APPEARED IN REF. 9.


   REFERENCES
      1.-  BOULTIF, A. AND LOUER, D., POWDER PATTERN INDEXING WITH THE
           SUCCESSIVE DICHOTOMY METHOD.
           J. APPL. CRYST. 37, 724-731 (2004).
      2.-  LOUER, D. AND LOUER, M., METHODE D'ESSAIS ET ERREURS POUR
           L'INDEXATION AUTOMATIQUE DES DIAGRAMMES DE POUDRE,
           J. APPL. CRYST. 5, 271-275 (1972).
      3.-  LOUER, D. AND VARGAS, R., INDEXATION AUTOMATIQUE DES
           DIAGRAMMES DE POUDRE PAR DICHOTOMIES SUCCESSIVES,
           J. APPL. CRYST. 15, 542-545, (1982).
      4.-  BOULTIF, A. AND LOUER, D., INDEXING OF POWDER DIFFRACTION
           PATTERNS FOR LOW SYMMETRY LATTICES BY THE SUCCESSIVE
           DICHOTOMY METHOD, J. APPL. CRYST. 24, 987-993 (1991).
      5.-  LOUER, D., AUTOMATIC INDEXING: PROCEDURES AND APPLICATIONS, IN
           'ACCURACY IN POWDER DIFFRACTION II', NIST, SPEC. PUBL. No. 846,
           GAITHERSBURG, MD, USA, pp. 92-104, 1992.
      6.-  LOUER, D. AND BOULTIF, A., INDEXING WITH THE SUCCESSIVE DICHOTOMY
           METHOD, DICVOL04, Z. KRISTALLOGR. 23, 225-230 (2006).
      7.-  DE WOLFF, P.M., A SIMPLIFIED CRITERION FOR THE RELIABILITY
           OF A POWDER PATTERN INDEXING, J. APPL. CRYST. 5, 108-113 (1968).
      8.-  SMITH, G. S. AND SNYDER, R. L., F(N): A CRITERION FOR RATING
           POWDER DIFFRACTION PATTERNS AND EVALUATING THE RELIABILITY
           OF POWDER-PATTERN INDEXING, J. APPL. CRYST. 12, 60-65 (1979).
      9.-  LOUER, D. AND BOULTIF, A., POWDER PATTERN INDEXING AND THE
           DICHOTOMY ALGORITHM, Z. KRISTALLOGR., IN PRESS (2007).