COL  ICSD Collection Code 9327
 DATE Recorded Sep 24, 1986; updated Nov 10, 1997
 NAME Silicon dioxide - alpha
 MINR Cristobalite low - from Ellora, Hyderabad, India
 FORM Si O2
      = O2 Si
 TITL Reinvestigation of the structure of low Cristobalite
 REF  Zeitschrift fuer Kristallographie, Kristallgeometrie, 
      Kristallphysik, Kristallchemie (-144,1977)
      ZEKGA 121 (1965) 369-377
 AUT  Dollase W A
 CELL a=4.978 b=4.978 c=6.948 à=90.0 á=90.0 ç=90.0
      V=172.2 Z=4
 SGR  P 41 21 2     (92) - tetragonal
 CLAS 422   (Hermann-Mauguin) - D4  (Schoenflies)
 PRS  tP12
 ANX  AX2
 PARM Atom__No OxStat  Wyck ---X--- ---Y--- ---Z---  -SOF-
      Si     1  4.000    4a  0.30004 0.30004 0.
      O      1 -2.000    8b  0.23976 0.10324 0.17844
 WYCK b a
 ITF  Si  1   B=0.83
 ITF  O   1   B=1.55
 REM  TWI (twinned crystal)
 REM  M PDF 39-1425
 RVAL 0.044