Schiavinatoite
      Diffraction data computed using the structure from the paper listed below, 
      along with the cell parameters refined from single crystal data of R090010
      Demartin F, Diella V, Gramaccioli C M, Pezzotta F
      European Journal of Mineralogy 13 (2001) 159-165
      Schiavinatoite, (Nb,Ta)BO4, the Nb analogue of behierite

      CELL PARAMETERS:   6.2252  6.2252  5.4811   90.000   90.000   90.000
      SPACE GROUP: I4_1/amd  

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Nb     0.00000   0.00000   0.00000     0.520     0.257
            Ta     0.00000   0.00000   0.00000     0.480     0.257
            B      0.00000   0.00000   0.50000     1.000     0.440
            O      0.00000   0.17920   0.32390     1.000     0.380

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  5 +/-  5 +/-  5
            MAX. ABS. INTENSITY / VOLUME**2:      158.9531391    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                21.60        100.00        4.1138    1   0   1
                28.68         83.91        3.1126    2   0   0
                36.19         36.52        2.4822    2   1   1
                38.70         48.93        2.3265    1   1   2
                41.01         13.93        2.2009    2   2   0
                44.02          3.27        2.0569    2   0   2
                46.81         28.58        1.9406    3   0   1
                52.18         18.57        1.7531    1   0   3
                55.83         25.32        1.6468    3   2   1
                57.65         42.40        1.5988    3   1   2
                59.39         11.26        1.5563    4   0   0
                60.62         11.43        1.5275    2   1   3
                63.96          8.62        1.4556    4   1   1
                67.26          8.61        1.3920    4   2   0
                68.42          5.28        1.3713    3   0   3
                68.47          2.27        1.3703    0   0   4
                73.16         12.84        1.2936    3   3   2
                75.81          3.73        1.2549    3   2   3
                75.86          7.94        1.2541    2   0   4
                78.83          2.47        1.2141    5   0   1
                78.83          8.96        1.2141    4   3   1
                82.96          5.62        1.1639    4   1   3
                83.02          7.22        1.1633    2   2   4
                85.93          3.07        1.1311    5   2   1
                87.46          9.25        1.1152    5   1   2
                88.94          2.48        1.1005    4   4   0
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.