  54
beta Tridymite (SiO_2) & P6_3/mmc (#194, D^4_{6h}) & hP12                      
O     -2.52600000     1.45838678     2.06750000
O     -2.52600000    -1.45838678     6.20250000
Si    -2.52600000     1.45838678      .51274000
Si    -2.52600000    -1.45838678     4.64774000
Si    -2.52600000     1.45838678     3.62226000
O     -3.78900000    -2.18758017      .00000000
O     -3.78900000     2.18758017      .00000000
O     -2.52600000      .00000000      .00000000
O     -3.78900000    -2.18758017     4.13500000
O     -3.78900000     2.18758017     4.13500000
O     -2.52600000      .00000000     4.13500000
Si    -2.52600000    -1.45838678     7.75726000
O     -3.78900000    -2.18758017     8.27000000
O     -3.78900000     2.18758017     8.27000000
O     -2.52600000      .00000000     8.27000000
O       .00000000     2.91677356     6.20250000
Si      .00000000     2.91677356     4.64774000
O     -1.26300000     2.18758017      .00000000
O       .00000000     4.37516034      .00000000
O     -1.26300000     2.18758017     4.13500000
O       .00000000     4.37516034     4.13500000
Si      .00000000     2.91677356     7.75726000
O     -1.26300000     2.18758017     8.27000000
O       .00000000     4.37516034     8.27000000
O       .00000000    -2.91677356     2.06750000
Si      .00000000    -2.91677356      .51274000
Si      .00000000    -2.91677356     3.62226000
O     -1.26300000    -2.18758017      .00000000
O       .00000000    -4.37516034      .00000000
O     -1.26300000    -2.18758017     4.13500000
O       .00000000    -4.37516034     4.13500000
O     -1.26300000    -2.18758017     8.27000000
O       .00000000    -4.37516034     8.27000000
O      2.52600000     1.45838678     2.06750000
O      2.52600000    -1.45838678     6.20250000
Si     2.52600000     1.45838678      .51274000
Si     2.52600000    -1.45838678     4.64774000
Si     2.52600000     1.45838678     3.62226000
O      1.26300000    -2.18758017      .00000000
O      1.26300000     2.18758017      .00000000
O      2.52600000      .00000000      .00000000
O      1.26300000    -2.18758017     4.13500000
O      1.26300000     2.18758017     4.13500000
O      2.52600000      .00000000     4.13500000
Si     2.52600000    -1.45838678     7.75726000
O      1.26300000    -2.18758017     8.27000000
O      1.26300000     2.18758017     8.27000000
O      2.52600000      .00000000     8.27000000
O      3.78900000     2.18758017      .00000000
O      3.78900000     2.18758017     4.13500000
O      3.78900000     2.18758017     8.27000000
O      3.78900000    -2.18758017      .00000000
O      3.78900000    -2.18758017     4.13500000
O      3.78900000    -2.18758017     8.27000000
