Pyrolusite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R040153
      Wyckoff R W G
      Crystal Structures 1 (1963) 239-444
      Second edition. Interscience Publishers, New York, New York
      Note: beta phase of MnO2, rutile structure

      CELL PARAMETERS:   4.404880   4.404880   2.870902   90.00000   90.00000   90.00000
      SPACE GROUP: P4_2/mnm
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                28.63        100.00        3.1147    1   1   0
                37.36         54.73        2.4052    1   0   1
                40.94          9.48        2.2024    2   0   0
                42.80         13.30        2.1110    1   1   1
                46.03          4.08        1.9699    2   1   0
                56.62         52.46        1.6243    2   1   1
                59.29         14.91        1.5574    2   2   0
                64.90          6.82        1.4355    0   0   2
                67.14          8.50        1.3929    3   1   0
                72.20         16.05        1.3072    3   0   1
                72.43          9.27        1.3037    1   1   2
                79.66          2.63        1.2026    2   0   2
                86.50          4.94        1.1241    3   2   1
                88.77          2.70        1.1012    4   0   0
                88.77          2.70        1.1012    4   0   0
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.