Jacobsite
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from single crystal data of R070719
      Lucchesi S, Russo U, Della Giusta A
      European Journal of Mineralogy 9 (1997) 31-42
      Crystal chemistry and cation distribution in some
      Mn-rich natural and synthetic spinels
      Sample: JBS4

      CELL PARAMETERS:   8.5099  8.5099  8.5099   90.000   90.000   90.000
      ALTERNATE SETTING FOR SPACE GROUP: Fd3m      

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Mg     0.12500   0.12500   0.12500     0.052     0.861
            Mn     0.12500   0.12500   0.12500     0.703     0.861
            Fe     0.12500   0.12500   0.12500     0.239     0.861
            Zn     0.12500   0.12500   0.12500     0.007     0.861
            Mg     0.50000   0.50000   0.50000     0.038     0.829
            Al     0.50000   0.50000   0.50000     0.015     0.829
            Fe     0.50000   0.50000   0.50000     0.882     0.829
            Mn     0.50000   0.50000   0.50000     0.065     0.829
            O      0.26100   0.26100   0.26100     1.000     0.955

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  7 +/-  7 +/-  7
            MAX. ABS. INTENSITY / VOLUME**2:      76.11579472    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                18.05         13.98        4.9132    1   1   1
                29.69         29.10        3.0087    2   2   0
                34.97        100.00        2.5658    3   1   1
                36.58          8.44        2.4566    2   2   2
                42.49         22.24        2.1275    4   0   0
                52.69          8.80        1.7371    4   2   2
                56.16         28.72        1.6377    5   1   1
                56.16          5.01        1.6377    3   3   3
                61.66         41.26        1.5044    4   4   0
                64.82          1.58        1.4384    5   3   1
                69.91          2.90        1.3455    6   2   0
                72.89          8.31        1.2977    5   3   3
                73.87          4.15        1.2829    6   2   2
                77.75          2.65        1.2283    4   4   4
                85.36          3.57        1.1372    6   4   2
                88.19          6.67        1.1079    7   3   1
                88.19          5.54        1.1079    5   5   3
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       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.