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resource.dat



Original Japanese manual, 29 March 1998, T. Higashi. Translated from Japanese 5 June 2006 TH.

Contents


   1) Overview
   2) Syntax
   3) Keyphrases
	3-1. Crystal data
	3-2. Crystal orientation
	3-3. Image frames
	3-4. Experimental conditions
	3-5. Evaluation of integrated intensities
	3-6. X-ray source
	3-7. Mosaic spread
	3-8. Geometry
	3-9. Other parameters
	3-10. Strategy of refinement
	3-11. Scanner
	3-12. Goniometer

1) Overview


  Parameters and information required for data processing are stored in a file called 
  resource.dat. Most programs will update the resource.dat file upon completion.  Items 
  written in the resource.dat file are usually minimum requirements; some items that are 
  not written are instead supplied by appropriate (or in some cases irresponsible!) 
  default values.

  So what are the minimum requirements? Assume that we collect diffraction images with an 
  RAXIS-IV. The X-ray source is CuKa and the source, goniometer and detector are in a
  typical geometry.  The minimum requirements might be as follows:

        Name of crystal:        unknown
        Scanner type:           RAXIS-IV
        Target element:         Cu  (or just specify the wavelength.)
        Distance from crystal to detector:   100 mm
        Coordinates of detector center:      (150,150) mm
        Template for frame files:  test???.img

  Then the resource.dat would contain the following:

        crystal name:           unknown
        scanner:                RAXIS-IV
        target:                 Cu
        crystal to detector distance: 100 mm
        detector center:        150 150 mm
        frame template:         test###.img

  These minimum reqirements are enough to start processing.

2) Syntax


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  The syntax of the resource.dat file is simple, with the format

        keyphrase: value(s)

  The end of each keyphrase must be a colon ':'.  One line must contain one unit of 
  information.  The values are usually single entities, but in some cases multiple values
  are required, depending on the keyphrase.

  The order in which the keyphrases appear in the file is not important, and the value
  are not case-sensitive.

  There are a few rare keyphrases that take no values, in some cases information may be
  spread over multiple lines. An example of the former is

        integrate in memory

  (This phrase indicates that each frame image is read and processed entirely in memory.)

  An example of the latter is 

        frame list:
              1  0  2
              2  2  4
              3  4  6
        end of frame list

  (This example is used when the frames contain no header information specifying the 
  oscillation range. In the example, the oscillation range of frame #1 is 0-2°, and 
  that of #2 is 2-4°. When unit information is spread over multiple lines, the last 
  line must be an "end" line.)

  Blank lines are allowed in the resource.dat file. Lines having the  '%' or '!' 
  characters in the first column are comment lines. Note that comment lines are skipped 
  when the resource.dat file is read, and therefore disappear when the file is updated.   

3) Keyphrases

3-1. Crystal data


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  crystal name: name of a crystal, or memo

  cell: unit cell parameters.
        6 values: a, b, c, α, β, and γ, items separated by one or more space characters.
        All 6 values are required; none may be ommitted. Units of a, b, c are Å and those
        of α, β, and γ are degrees. When standard errors are included, they are given in 
        parentheses, i.e. "Acta Crystallographica" style.

  molecule: "macromolecule" or "small molecule"
        Suitable default values for macromolecule or small molecule processing will be 
        chosen based on this keyword.

  laue class: a Laue class symbol, one of
        -1 | 2/m | mmm | 4/m | 4/mmm | 6/m | 6/mmm | -3 | -3m | -3m1 | -31m | m-3 | m-3m 

  lattice type: lattice type character, one of
        P | A | B | C | I | F | R

  crystal system: Name of the crystal system, one of
        triclinic | monoclinic | orthorhombic | hexagonal | trigonal | tetragonal | cubic

  formula: chemical or molecular formula
        For example, C10H20. No spaces should appear within the formula.

  Z value: Number of formula units per unit cell.

  The chemical formula and Z value are only useful for small molecule samples. They are 
  necessary for some calculations, such as absorption corrections.

3-2. Crystal orientation


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  rotation and x-ray axes: crystal axes parallel to, or nearest to, the spindle crystal 
        rotation axis and the incident X-ray direction.  The axes are indicated by strings
        that represent either a real axis name  (+a | +b | +c | -a | -b | -c) or a
        reciprocal axis name (+a* | +b* | +c* | -a* | -b* | -c*).  Mixed use of real and
        reciprocal axis names is allowed.

  crystal missetting angles: crystal orientation angles φx, φy, and φz, in degrees.

  "rotation and x-ray axes" and "crystal misssetting angles" may be given when the crystal 
  orientation is known beforehand. More commonly this information is produced by the 
  indexing process.

3-3. Image frames


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  frame template: frame filename template, e.g. demo###.img, or ../frame/abc???.osc.  
        Both full path and relative path specifications are allowed. Windows systems
        normally expect the '\' (backslash) character as the folder separator, but  
        here either the forward-slash or backslash is allowed.  The hash '#' or question-
        mark '?' characters are used as wildcards to represent sequential numbers 
        representing the frame numbers.

  present frame file: frame filename which is currently being processed.
        This line is used by the programs to get the current framename. This value should
        not normally be modified by the user.

  present intensity file: intensity filename currently being processed.
        This value is also not modified by the user.

  frame list:
        This keyphrase indicates that frame list information follows in subsequent
        lines. This functionality is used when frames have no header and hence frame
        information such as oscillation range must be supplied. Most modern instruments
        provide frames containing full header information so this keyphrase is often
        unused.

        Frame infomation supplied by the following lines are
              1. serial number of a framefile
              2. oscillation start angle
              3. oscillation end angle
              4. center of detector, xcen and ycen, in mm
              5. coupling constants, couplex and coupley, when Weissenberg 
                 movement of detector is applied.

        This information should be supplied one line per frame. For these 5 items, 1-3 
        are compulsory while the remainder (4-5) are optional. The detector center is 
        necessary when separate imaging plates are used and their detector centers
        are significantly different. When omitted, the programs use information given 
        by the keyphrase "detector center".

        End of frame list is shown by the "end of list" line.

        An example of the frame list is

              frame list:
                    1 0 3
                    2 3 6
                    3 6 9
              end of frame list

        It is possible to have the frame list in a different file and to include it. 
        In such case, use the following syntax:

                frame list: "include filename"

3-4. Experimental conditions


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  The information contained in this section is only for record keeping. These values are
  not used in any calculations.

  crystal size:  sizex sizey sizez

  crystal color: color name

  crystal habit: shape of the sample crystal

  experiment temperature:  temperature in deg. C

  collimator diameter: diameter in mm

  exposure time per degree:  exposure time in seconds per one degree

  XG current:  current of X-ray generator in mA

  XG voltage:  volotage of X-ray generator in mV

3-5. Evaluation of integrated intensities


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  measurement box parameters: nx ny nc mx my
        These 5 integer values are measurement box parameters as used in the 
        MOSFLM package. Refer the following figure:

		A-E--M---------------N--F-B
		G-|-/-----------------\-|-H
		| |/                   \| |
		| /                     \ |
		|/|                     |\|
		O |                     | P
		| |         peak        | |
		Q |                     | R
		|\|                     |/|
		| \                     / |
		| |\                   /| |
		I-|-\-----------------/-|-J
		C-K--S---------------T--L-D

        The 5 parameters are integers representing pixel units. Their definitions are:

              nx=AB=CD,          ny=AC=BD
              mx=AE=FB=CK=LD,    my=AG=IC=BH=JD
              nc=AM=NB=AO=BP=CQ=CS=DR=DT

        The peak area is defined by the inner area of the figure. The background is 
        defined by the outer area of the figure. The border separating the peak and 
        background areas is a buffering line and is not included in the intensity 
        calculations.

        nx and ny must be odd numbers, in order to define the center of the measurement
        box. mx, my, nc have no such restriction. 

        For example, box parameters 17 15 6 2 2 give the following figure, where the 
        peak area is shown by '.', background area by '+' and border lines by '*'.

	      + + + + + + + + + + + + + + + + +
	      + + + + + + + + + + + + + + + + +
	      + + + + * * * * * * * * * + + + +
	      + + + * . . . . . . . . . * + + +
	      + + * . . . . . . . . . . . * + +
	      + + * . . . . . . . . . . . * + +
	      + + * . . . . . . . . . . . * + +
	      + + * . . . . . . . . . . . * + +
	      + + * . . . . . . . . . . . * + +
	      + + * . . . . . . . . . . . * + +
	      + + * . . . . . . . . . . . * + +
	      + + + * . . . . . . . . . * + + +
	      + + + + * * * * * * * * * + + + +
	      + + + + + + + + + + + + + + + + +
	      + + + + + + + + + + + + + + + + +

  [Modified for fine-slice method]  added by TH 2006 June

  [Peak defined by ellipsoid]

  The measurement box defintion given above is the exactly that of the MOSFLM package
  and it has been used for the "wide-slice" method. When the "fine-slice" method was
  developed, the above definition was found to be impractical, so the definition 
  has been updated. 

  The currently adopted measurement box is:

            + + + + + + + + + + + + + + + + +
            + + + + + + + + + + + + + + + + +
            + + + + + + + + . + + + + + + + +
            + + + + + . . . . . . . + + + + +
            + + + + . . . . . . . . . + + + +
            + + + . . . . . . . . . . . + + +
            + + + . . . . . . . . . . . + + +
            + + . . . . . . . . . . . . . + +
            + + + . . . . . . . . . . . + + +
            + + + . . . . . . . . . . . + + +
            + + + + . . . . . . . . . + + + +
            + + + + + . . . . . . . + + + + +
            + + + + + + + + . + + + + + + + +
            + + + + + + + + + + + + + + + + +
            + + + + + + + + + + + + + + + + +

  The box is obtained this way:

    1. Let aa, bb, a, and b be nx/2, ny/2, nx/2-mx, and ny/2-my, respectively.
    2. Let x and y be the distance calculated from the center of the measurement box.
    3. The peak area is defined as (x*x)/(a*a) + (y*y)/(b*b) ≤ 1.
    4. The background area is defined as pixels with |x| ≤ aa and |y| ≤ bb and which 
       are outside of the peak area.
    5. Parameter nc is not used.

  [Background defined by ellipsoid]

  When two spots appoach diagonally, the relatively large background areas at the four
  corners of the box may cause an undesirable situation. To avoid this, an alternative 
  measurement box can be defined as follows.

            * * * * * * * * + * * * * * * * *
            * * * * + + + + + + + + + * * * *
            * * * + + + + + . + + + + + * * *
            * * + + + . . . . . . . + + + * *
            * + + + . . . . . . . . . + + + *
            * + + . . . . . . . . . . . + + *
            * + + . . . . . . . . . . . + + *
            + + . . . . . . . . . . . . . + +
            * + + . . . . . . . . . . . + + *
            * + + . . . . . . . . . . . + + *
            * + + + . . . . . . . . . + + + *
            * * + + + . . . . . . . + + + * *
            * * * + + + + + . + + + + + * * *
            * * * * + + + + + + + + + * * * *
            * * * * * * * * + * * * * * * * *

  This box is obtained this way:

    1. Let aa, bb, a, and b be nx/2, ny/2, nx/2-mx, and ny/2-my, respectively.
    2. Let x and y be the distance calculated from the center of the measurement box.
    3. The peak area is defined as (x*x)/(a*a) + (y*y)/(b*b) ≤ 1.
    4. The background area is defined as pixels with (x*x)/(aa*aa) + (y*y)/(bb*bb) ≤ 1 
       and which are outside of the peak area.
    5. Points outside of the background area are not included in intensity calculations.

  I have tested both boxes but I could not decide whichi is better. Weak point
  of the latter box is that reliability of background intensity is reduced because
  of relatively small number of background sampling points. 

  In the current integration programs, the user can select one of the above background
  methods by choosing the appropriate program arguments.



  intensity evaluation method: any of the following 5 phrases

        box sum                   [simple sum of pixel intensities]
        regional profile fitting  [Rossmann's regional profile fitting]
        profile fitting           [same as above]
        local profile fitting     [standard profile from surrounding spots]
        seed-skewness method      [seed-skewness method (Bolotovsky et al.)]

        'integration evaluation method' is only valid for the wide-slice method.
        For fine-slice frames, there is no choice of integration method; only the
        'box sum' method is applicable.

        (a) Rossmann's regional profile method

        The detector surface is divided into 5 regions. Standard profiles are generated for
        each region and integrated intensities are calculated using these standard profiles. 
        The 5 regions are:

        region 1:   d > resolution limit x 2.236
        region 2:   outside of region 1 and x > xcen, y > ycen
        region 3:   outside of region 1 and x < xcen, y > ycen
        region 4:   outside of region 1 and x > xcen, y < ycen
        region 5:   outside of region 1 and x < xcen, y < ycen

        where (xcen,ycen) is the detector center.

        (b) local profile method

        A standard profile of any spot is generated by stronger spots surrounding 
        that particular spot. Currently, N spots with I > 1σ(I) are used. N is
        given by the keyphrase "local profile generating spots:".

        (c) seed-skewness method

        The size of the measurement box for a spot is generated by the pixel intensity
        distribution of the spot. Evaluation of the integrated intensity is the same as in 
        the box sum method. For details of the seed-skewness method, see Bolotovsky, 
        White, Darovsky & Coppens(1995). J. Appl. Cryst. 28, 86-95.

  measurement box type: fix, alpha12 or "tangential pt pr"
        This keyphrase is related to the size of the measurement box.  "fix" indicates 
        a fixed-size measurement box everywhere on the detector surface. "alpha12" 
        indicates that the box size is enlarged in proportion to the Kα1-Kα2 splitting 
        of a spot. Moreover, the choice of "alpha12" generates two measurement boxes, 
        one at the center calculated for Kα1 and the other at Kα2. The logical OR of 
        the two peak areas is used for integration. This box enlargement is only done  
        when "intensity evaluation method" is "box sum". Selection of any profile 
        fitting forces the use of a fixed measurement box.

        The default value of this keyphrase is 'alpha12'.

        The keyword "tangential" is a special value. When the mosaic spread of a sample 
        crystal is large, e.g. 2-3°, diffraction spots tend to be expanded also along the
        2θ-constant direction (tangential direction), and the diffraction pattern may 
        take on the look of a preferred-orientation powder sample. In these cases, an 
        ordinary box can not accomodate the elongated spots. A tangential box has edges
        that are parallel to the 2θ-constant direction (tangential direction) and the
        2θ-increasing direction (radial direction). Their lengths are determined
        by the equations:
                nt = nx' + dist * pt
                nr = ny' + dist * pr
        where nt and nr are lengths of a measurement box along the tangential and 
        radial directions, pt and pt are constants corresponding to increasing 
        rates of length and supplied by the "tangential pt pr" key, and nx' and ny'
        are nx and ny of the measurement box parameters. Dist is distance of the spot
        from the detector center and is proportional to the d* length. Therfore the size 
        of the tangential measurement box is enlarged in proportion to the d* value.
	

  spot size: approximate spot size in mm
        Two values along x- and y-directions are required. These sizes are used
        to evaluate spot overlap. Default values are 0.5 0.5 mm.

  resolution limit: resolution limit for integration, in Å. 

  maximum two-theta: 2θ limit for integration, in degrees. This is an alternative 
        expression of the above resolution limit.

  inner resolution limit: lower resolution limit for integration, in Å.

  minimum allowed overload pixels: number of allowed overload pixels within a spot.
        If overloaded pixels exist in a spot, the program will not treat the spot as
        overloaded if the number of overloaded pixels is less that this value.
        The default value is 0.

  minimum allowed underloaded pixels: number of allowed pixels with zero intensity.
        Default value is 0.

  integration in memory
        This keyphrase has no value. When this keyphrase is given, an entire frame 
        image is read in random access memory, and integration is done. If this 
        keyphrase is not given, a frame image is read line by line.
      
        This keyphrase was useful when cpu memory was tight. Now that computer memory
        is plentiful, this keyphrase is no longer useful. 

  shared memory: spring8 or normal
        This indicates use of unix shared memory to store frame image in memory.
        This phrase is no longer valid. 

3-6. X-ray source


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  target: element symbol of target material.  Cu, Mo, or SR.
        Cu or Mo specifies the target element, and hence indicates wavelength as well.
        SR indicates a synchrotron X-ray source, where the wavelength must be entered
        explicitly. When the target element is neither Cu nor Mo, the target should be 
        specified as SR and the wavelength explicitly specified.

  wavelength: wavelength of source X-ray, in Å.
        When the target is given as Cu or Mo, wavelength is taken from the wavelength
        database, so that this keyphrase is unnecessary. 

  wavelength alpha_1_2: λ(Kα1) λ(Kα2)
        When target is given as Cu or Mo, this keyphrase is unnecessary.

  energy resolution: Δλ/λ
        When target is Cu or Mo, the energy resolution is calculated as
        |λ(Kα1)-λ(Kα2)|/λ(Kα).

  monochromator material: Graphite or CMF
	This keyword is only necessary for the two materials listed. If mirrors or a Kβ 
	filter are used, this keyword should be removed and the two-theta value set to 0.

  monochromator two-theta: monochromator 2θ angle in degrees. This value is used for the 
        polarization factor calculation. When a Kβ filter is used, this angle should be 
        0. For mirror optics without a monochromator, again this value should be 0. The
        default assumes that the monochromator material is graphite, and the 2θ angle
        is calculated.

  monochromator d value: interplanar distance of the monochromator material in Å.
        This keyphrase can be replaced with "monochromator two-theta".

  linear polarization factor of SR: 
        Linear polarization factor of synchrotron radiation J is defined as
        J=(Iσ-Iπ)/(Iσ+Iπ), where Iσ is the intensity of a horizontally polarized 
        X-ray and Iπ is that of a vertically polarized X-ray.

3-7. Mosaic spread


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  mosaic spread: effective mosaic spread of a sample crystal in degrees. Normally the
        X-ray beam crossfire is set to 0. This effective mosaic spread includes the 
        effect of beam crossfire. Default is 0.5°.

  horizontal beam crossfire: divergence angle of incident X-ray along the horizontal
        direction. Default is 0.

  vertical beam crossfire: divergence angle of incident X-ray along the vertical
        direction. Default is 0.

  Note: The approximate values for mosaic spread with a CuKα X-ray source and a
  graphite monochromator are as follows:

            mosaic spread of sample crystal:      ~0.1°
            horizontal beam crossfire:            ~0.3-0.4°
            vertical beam crossfire               ~0.2°
            energy resolution                     ~0.002

  Therefore, the effective mosaic spread should be 0.3-0.4°. It is safe to use a value
  of 0.5 as a default. 

3-8. Geometry


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  detector center: xcen ycen (mm)
        Center of detector, or more logically, the coordinates of a point defined by
        a line passing through the crystal and normal to the detector. For a well- 
        adjusted diffractometer, this point agrees with the trace of the direct beam.

  crystal to detector distance: distance, in mm.
        The distance between center of the crystal and the detector center.

  cylinder radius: cylinder radius in mm, when a cylindrical detector is used.
        The radius is independent of the above distance. Usually "cylinder 
        radius" and "crystal to detector distance" are the same, but there is no
        restriction that this be true.

  coupling constants: horizontal and vertical coupling constants (mm/°).
        When Weissenberg geometry is used for data collection, the horizontal and vertical 
        coupling constants are the ratio of detector movement to spindle angle rotation. 
        When these are written in the frame header, this keyphrase is not used.

3-9. Other parameters


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  detector shift vector: detector shift parameters, Dx, Dy, Dz (mm)
        The "detector center" and "crystal to detector distance" are treated as constants,
        virtually modified by these three vectors. Dx and Dy are the adjusted offsets of the
        detector center (xcen,ycen) and Dz is that of distance. This value is automatically 
        entered and updated after refinement.

  detector setting angles: Dα, Dβ, Dγ (°)
        Adjustable (refine) values of detector rotation angles along the x-, y-, and z-axes. 
        This value is automatically entered and updated after refinement.

  source missetting angles: slight rotation angles applied to the incident X-ray
        vector, s,s,s
        A current restriction is that s=s=0. Only s has a non-zero value, which is 
        equal to the so-called spindle inclination angle. This line is automatically 
        entered and updated after refinement.

3-10. Strategy of refinement


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  refinement list:
        The programs refosc (with -g option) and fs_collect read these refinement lists 
        and do refinement sequentially according to the refinement conditions given
        here. The strategy starts from the keyphrase "refinement list:" and ends 
        with "end of refinement list".

        Each refinement condition is written in a line, consisting of
              Resolution limit (Å)
              Number of refinement cycles
              List of refinement parameters

        "List of refinement parameters" is a list of brevity codes, indicating
        parameters to be refined in the refinement cycle. The brevity codes are
        CELL | ROT | DSHIFT | DIST | CENT | DROT | SROT | RADIUS | WAVE.
        These codes are separated by commas; no space is allowed in the "List of 
        refinement parameters".

        CELL     Unit cell parameters, a b c α β γ. The number of free
                 variables depends upon the symmetry of unit cell.
        ROT      Crystal rotation angles φx, φy, φz.
        DSHIFT   Detector shift parameters, Dx, Dy, Dz
        DIST     Refine Dz separately, of 3 parameters of DSHIFT
        CENT     Refine Dx and Dy only (first 2 parameters of DSHIFT)
        DROT     Detector rotation angles, Dα, Dβ, Dγ.   
        SROT     Source rotation angles, s, s, s. 
        RADIUS   Cylinder radius (when cylindrical detector is used)
        WAVE     Wavelength, but not advised unless SR source and ambigious
                 wavelength

        Current default refiment list for small molecule is

            refinement list:
            1.5 5 cent
            1.5 5 cent
            1.5 5 rot,cent
            1.0 5 cell,rot,cent,dist,drot,srot
            1.0 5 cell,rot,cent,dist,drot,srot
            0.8 5 cell,rot,cent,dist,drot,srot
            0.8 5 cell,rot,cent,dist,drot,srot
            end of refinement list

        and that for macromolecule is

            refinement list:
            3.0 5 rot,cent
            2.5 5 cell,rot,cent,dist,drot,srot
            2.5 5 cell,rot,cent,dist,drot,srot
            2.0 5 cell,rot,cent,dist,drot,srot
            2.0 5 cell,rot,cent,dist,drot,srot
            end of refinement list

        The strategy can be written in a separate file and included by the
        description:

            refinement list: "include file name"

3-11. Scanner


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  scanner: Scanner code. Allowed are:

        RAPID       Rigaku RAXIS-RAPID or RAXIS-RAPID-II
        RAPIDF      Rigaku RAXIS-RAPID with fixed chi goniometer
        RAXIS2      Rigaku RAXIS-II
        RAXIS4      Rigaku RAXIS-IV or RAXIS-IV++
        RAXIS7      Rigaku RAXIS-VII
        RAXISCS     Rigaku RAXIS-CS
        RAXIS-HR    Rigaku RAXIS-HR
        RAIXS-HR-Q  Rigaku RAXIS-HR with quarter-chi goniometer
      
        MERCURY     Rigaku MERCURY CCD diffractometer
        AFC7-MERCURY   Rigaku MERCURY on AFC7 goniometer
        JUPITER     Rigaku JUPITER CCD diffractometer
        JUPITER40   Rigaku JUPITER40
        SATURN      Rigaku SATURN
        SATURN70    Rigaku SATURN70
        SATURN92    Rigaku SATURN92
        SCX-MINI    Rigaku SCX-MINI diffractometer

        DIP         MacScience DIP IP diffractometer
        QUANTUM     ADSC QUANTUM diffractometer
        ADSC        ADSC CCD diffractometer at SPring-8
        OXFORD      Oxford CCD diffractometer at SPring-8

        BAS2000     Fuji BAS2000 IP scanner
        BAS2000D    Fuji BAS2000 IP scanner recorded in 10-bit mode

        UNKNOWN     unknown detector

        * BAS2000 and BAS200D are offline scanners. In order to process data
        recorded on BAS2000, BAS2000D and UNKNOWN, additional information
        described below is required.

  scan order: a string representing scan order. Allowed strings are

        +H+V | -H+V | +H-V | +V+H | -V+H | +V-H | -V-H

        where H and V indicate horizontal and vertical directions. 
        When the fast-varying direction is horizontal and the slow-varying
        direction is vertical, put H first and V last. The sign shows the 
        scan direction as

        +H: horizontal scan, left to right
        -H: horizontal scan, right to left
        +V: vertical scan, bottom to top
        -V: vertical scan, top to bottom

        In RAXIS4 or RAPID case, this line is +H+V, though unnecessary.

  pixel size: pixel size in mm along vertical direction

  pixel size aspect ratio: 
            (pixel size along horizontal)/(pixel size along vertical)

  record length: record length in pixels

  number of records: number of records

  bits per pixel: number of bits per pixel

  data type: either linear or log
           This specifies type of pixel intensity, linear data or log data.

  byte swap  Specify when image data format is swapped. This line has no value.

3-12. Goniometer


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  goniometer definition:
        This keyphrase and the following lines up to "end of goniometer
        definition" define a goniometer. There are 3 sub-keyphrases as:

        goniometer name: name_of_goniometer
        crystal circle:  axis_name nx ny nz angle offset start_angle end_angle
        detector circle: axis_name nx ny nz angle offset start_angle end_angle
    
        Number of "crystal circle" keyphrases may be 1-3, depending upon freedom of
        the goniometer. "detector circle" may be omitted when the detector is not
        on the goniometer.

        The definitions of nx, ny, nz and angle are a little bit complicated and 
        tricky. Usually, the rotational freedom of a goniometer is defined by its 
        rotation axis. In the present scheme, the rotation axis is described by a
        rotated z-axis. For example, "0 1 0 90" indicates that the rotation axis is
        the z-axis rotated by 90° along the (0 1 0) vector, ie. the rotation axis 
        is the x-axis. The merit of this notation is clear when defining the kappa-axis 
        of a kappa goniometer: if the alpha angle of the kappa goniometer is 55°, then 
        the kappa-axis is simply defined by 0 1 0 55. Another merit is that this 
        notation allows expression of slight misadjustment of a goniometer. For 
        example, if the kappa goniometer has a slight misadjustment in fixing the 
        kappa-axis by 0.01°, this scheme notation gives simply 0 1 0 55.01.

        The offset, start_angle and end_angle parameters are related to goniometer 
        rotation angles. Among them, start_angle and end_angle indicate the movable
        range of the goniometer axis, but they are not used in any calculation.
  
        The order of goniometer axes should be phi, chi and omega. Note that in the 
        case of a kappa-goniometer, the name "kappa" should be avoided and the name
        "chi" used instead.  

        The syntax of "detector circle" is exactly the same as that of "crystal circle", 
        but the name of the axis should be "2theta".

        An example for the RAXIS RAPID is

          goniometer definition
             goniometer name: RAPID
             crystal  circle:    phi  0.0  1.0  0.0 0.000000 0.000000 -360.0 720.0
             crystal  circle:    chi  0.0  1.0  0.0 90.000000 0.000000 -16.0 55.0
             crystal  circle:  omega  0.0  1.0  0.0 0.000000 0.000000 -85.0 265.0
          end of goniometer definition

       This goniometer definition is designed to allow almost any type of 
       goniometer. But, substantially, the scanner name defines goniometer. So, 
       usually "goniometer definition" is not compulsory.