Michael E. Fleet, 1998, Sodium Heptasilicate: A High-Pressure Silicate 
with Six-Membered Rings of Tetrahedra Interconnected by SiO6 Octahedra:
(Na8SiSi6O18). American Mineralogist, v.83, 618-624.


TABLE 3. List of observed and calculated structure factors

  H  K  L    FO     FC      H  K  L    FO     FC      H  K  L    FO     FC
  1  1  1    9.2    9.5     6  3  4    6.8    7.7    -1 -6 -2   18.1   18.3
  2  2  2   19.2   18.2     7  4  5    4.8    5.5     0 -5 -1   12.5   12.4
  3  3  3   38.6   39.0    -3 -6 -6    7.8    7.8     1 -4  0   20.8   21.3
  4  4  4   86.3   82.1    -2 -5 -5    5.3    5.4     2 -3  1   10.4   10.2
  5  5  5   23.8   24.1    -1 -4 -4    6.0    5.2     3 -2  2   30.9   31.3
 -5 -6 -6    7.4    7.9     0 -3 -3   18.9   18.9     4 -1  3    3.1    1.7
 -4 -5 -5    2.7    4.3     1 -2 -2   10.9   10.8     5  0  4   11.9   11.7
 -3 -4 -4    3.6    3.7     2 -1 -1   21.0   21.2     6  1  5    2.6    1.3
 -2 -3 -3   20.6   19.9     3  0  0   35.4   33.4     7  2  6   10.9   11.7
 -1 -2 -2   26.3   26.7     4  1  1    1.9    3.1    -3 -8 -5    0.0    2.7
  0 -1 -1   15.3   16.4     5  2  2   13.0   14.0    -2 -7 -4    2.8    0.4
  2  1  1   16.9   17.0     6  3  3    8.5    8.6    -1 -6 -3    5.6    6.5
  3  2  2    8.0    7.8     7  4  4    4.8    5.6     0 -5 -2   31.2   31.6
  4  3  3   12.5   12.9    -3 -7 -4    0.5    1.3     1 -4 -1   17.2   17.1
  5  4  4    8.1    6.9    -2 -6 -3    3.3    2.2     2 -3  0   10.8   10.4
  6  5  5    3.2    0.3    -1 -5 -2    9.5   10.2     3 -2  1   10.8   11.0
 -4 -6 -5    7.0    7.9     0 -4 -1    0.0    1.1     4 -1  2   27.0   26.7
 -3 -5 -4    4.5    4.6     1 -3  0   24.6   24.7     5  0  3   27.1   26.9
 -2 -4 -3   13.1   13.5     2 -2  1   20.1   20.1     6  1  4    5.9    5.4
 -1 -3 -2   21.9   21.4     3 -1  2   13.5   13.0     7  2  5    3.3    4.9
  0 -2 -1   23.2   23.6     4  0  3    6.1    7.2    -2 -7 -5    5.0    5.1
  1 -1  0   11.8   12.8     5  1  4   12.8   13.1    -1 -6 -4    5.0    5.5
  2  0  1   22.8   23.6     6  2  5    6.2    5.3     0 -5 -3   26.8   26.4
  3  1  2   21.7   21.0     7  3  6    4.9    3.0     1 -4 -2   26.5   26.7
  4  2  3   12.8   13.1    -3 -7 -5   13.5   15.4     2 -3 -1   10.3   10.6
  5  3  4    4.5    4.2    -2 -6 -4   37.4   37.2     3 -2  0    9.4   10.1
  6  4  5    7.4    7.8    -1 -5 -3   36.8   36.4     4 -1  1   17.3   17.3
 -4 -6 -6   17.0   18.6     0 -4 -2    6.8    6.4     5  0  2   31.4   31.7
 -3 -5 -5   34.2   31.9     1 -3 -1    4.5    4.4     6  1  3    5.7    6.4
 -2 -4 -4   16.0   16.3     2 -2  0  100.7  102.2     7  2  4    0.0    0.0
 -1 -3 -3   31.0   31.2     3 -1  1    5.5    4.5     8  3  5    0.0    2.5
  0 -2 -2  103.9  105.3     4  0  2    6.6    6.8    -2 -7 -6   11.2   12.0
  1 -1 -1   24.5   26.3     5  1  3   37.6   36.8    -1 -6 -5    2.3    1.1
  2  0  0   46.2   47.7     6  2  4   36.6   37.2     0 -5 -4   11.7   11.8
  3  1  1   26.2   27.0     7  3  5   16.0   15.2     1 -4 -3    3.0    1.9
  4  2  2   80.9   80.3    -3 -7 -6    3.5    3.1     2 -3 -2   31.9   31.5
  5  3  3   17.5   16.9    -2 -6 -5    5.4    5.3     3 -2 -1   10.4   10.2
  6  4  4    3.3    0.5    -1 -5 -4   13.4   13.2     4 -1  0   22.4   22.2
  7  5  5   20.4   24.0     0 -4 -3    6.4    7.6     5  0  1   12.4   12.2
 -4 -7 -5    4.3    5.5     1 -3 -2   14.0   13.3     6  1  2   18.3   18.5
 -3 -6 -4    6.2    7.6     2 -2 -1   20.3   20.1     7  2  3   10.7   10.6
 -2 -5 -3   10.0   10.0     3 -1  0   25.3   24.6     8  3  4    2.7    2.8
 -1 -4 -2   22.2   21.8     4  0  1    0.0    0.5    -1 -6 -6    9.4   10.6
  0 -3 -1    6.9    7.1     5  1  2   10.1   10.3     0 -5 -5    7.9    8.0
  1 -2  0   39.7   39.8     6  2  3    3.1    1.8     1 -4 -4    0.8    1.1
  2 -1  1   11.7   11.7     7  3  4    0.0    1.3     2 -3 -3   10.8   10.7
  3  0  2   31.6   30.5    -2 -6 -6   18.0   17.3     3 -2 -2   37.8   37.2
  4  1  3    1.4    0.9    -1 -5 -5   33.5   32.2     4 -1 -1    6.8    6.8
  5  2  4   17.4   17.2     0 -4 -4   86.2   84.0     5  0  0    0.0    0.6
  6  3  5    2.9    2.3     1 -3 -3   36.0   36.4     6  1  1   17.3   17.8
 -3 -6 -5    1.3    2.4     2 -2 -2   46.0   45.1     7  2  2   18.4   18.7
 -2 -5 -4   16.7   17.3     3 -1 -1   23.5   22.2     8  3  3    6.5    6.6
 -1 -4 -3    0.0    0.8     4  0  0  127.3  124.3    -2 -8 -3    0.7    2.5
  0 -3 -2   30.7   30.5     5  1  1    8.5    8.7    -1 -7 -2    5.2    5.4
  1 -2 -1   11.9   11.8     6  2  2   18.4   19.3     0 -6 -1    0.0    2.2
  2 -1  0   39.4   39.8     7  3  3   15.4   15.1     1 -5  0   20.6   20.9
  3  0  1    7.1    7.1     8  4  4   24.9   25.4     2 -4  1   10.2   10.0
  4  1  2   21.8   21.2    -3 -8 -4    0.0    2.0     3 -3  2   17.2   16.9
  5  2  3   10.6   10.1    -2 -7 -3   10.2   10.5     4 -2  3    9.9    9.2
  
  H  K  L    FO     FC      H  K  L    FO     FC      H  K  L    FO     FC
  5 -1  4    7.5    8.2     5 -2  4   23.6   23.8    -1 -9 -2    0.0    2.1
  6  0  5    9.3    9.1     6 -1  5    3.6    0.6     0 -8 -1    3.3    0.8
  7  1  6    0.0    1.8     7  0  6    0.0    0.5     1 -7  0    6.8    7.3
 -2 -8 -4    3.1    4.2    -1 -8 -3    4.1    4.8     2 -6  1    2.5    0.4
 -1 -7 -3   16.9   16.2     0 -7 -2    5.6    5.0     3 -5  2    2.8    2.9
  0 -6 -2   52.4   52.4     1 -6 -1   12.4   12.4     4 -4  3    1.7    1.3
  1 -5 -1   17.8   18.1     2 -5  0   30.7   30.7     5 -3  4    0.5    3.6
  2 -4  0   22.0   22.2     3 -4  1    7.3    6.9     6 -2  5    4.7    3.0
  3 -3  1   20.2   19.7     4 -3  2    8.6    8.3     7 -1  6    1.0    3.3
  4 -2  2   78.9   80.1     5 -2  3    4.0    1.9     0 -8 -2    2.0    0.7
  5 -1  3   13.5   13.8     6 -1  4   16.5   16.8     1 -7 -1    6.9    5.5
  6  0  4    1.8    3.1     7  0  5   10.6   10.8     2 -6  0   61.9   62.1
  7  1  5   32.3   29.7    -1 -8 -4    7.3    8.9     3 -5  1   25.1   25.2
 -2 -8 -5    5.9    7.3     0 -7 -3   21.0   20.8     4 -4  2    6.7    6.4
 -1 -7 -4    7.2    7.4     1 -6 -2   19.9   20.5     5 -3  3   23.7   22.7
  0 -6 -3   17.4   17.2     2 -5 -1    7.7    7.8     6 -2  4   47.7   47.4
  1 -5 -2    4.5    4.8     3 -4  0   19.9   20.3     7 -1  5    2.9    3.4
  2 -4 -1   26.3   26.0     4 -3  1    8.7    9.9     0 -8 -3    3.4    4.3
  3 -3  0   25.5   25.7     5 -2  2   31.4   31.2     1 -7 -2    1.1    2.1
  4 -2  1   26.4   26.1     6 -1  3    0.0    0.1     2 -6 -1    3.7    3.0
  5 -1  2    4.4    5.0     7  0  4   10.1   10.5     3 -5  0    0.0    0.3
  6  0  3   16.9   17.0     8  1  5    4.9    2.4     4 -4  1    4.3    4.7
  7  1  4    7.6    7.8    -1 -8 -5    4.9    2.4     5 -3  2    5.6    5.4
  8  2  5    4.5    7.5     0 -7 -4   10.2   10.7     6 -2  3    6.8    7.3
 -1 -7 -5   29.6   29.9     1 -6 -3    0.0    0.4     7 -1  4    2.3    0.4
  0 -6 -4    3.2    3.3     2 -5 -2   31.8   31.4     8  0  5    4.5    3.0
  1 -5 -3   12.8   13.4     3 -4 -1    9.6    9.7     0 -8 -4   41.1   40.7
  2 -4 -2   79.4   79.9     4 -3  0   20.8   20.4     1 -7 -3   14.2   14.4
  3 -3 -1   20.1   20.0     5 -2  1    9.2    8.5     2 -6 -2    6.5    6.0
  4 -2  0   22.7   22.6     6 -1  2   20.4   20.8     3 -5 -1   13.8   14.4
  5 -1  1   17.5   17.7     7  0  3   21.0   20.7     4 -4  0   98.6   96.1
  6  0  2   53.2   52.7     8  1  4    7.4    9.0     5 -3  1   14.4   14.4
  7  1  3   17.2   16.0     0 -7 -5   10.1   10.7     6 -2  2    5.7    5.8
  8  2  4    3.9    4.3     1 -6 -4   17.4   16.8     7 -1  3   14.1   14.4
 -1 -7 -6    3.2    2.4     2 -5 -3    1.9    1.9     8  0  4   40.2   40.9
  0 -6 -5    9.8    9.0     3 -4 -2    8.3    8.1     0 -8 -5    0.0    3.2
  1 -5 -4    7.9    8.4     4 -3 -1    7.1    7.0     1 -7 -4    0.0    0.4
  2 -4 -3   10.1    9.8     5 -2  0   30.9   30.4     2 -6 -3    7.0    7.6
  3 -3 -2   17.0   16.9     6 -1  1   12.4   12.8     3 -5 -2    5.1    5.5
  4 -2 -1    9.3    9.8     7  0  2    4.6    4.5     4 -4 -1    4.2    5.3
  5 -1  0   20.0   20.5     8  1  3    4.8    4.5     5 -3  0    2.2    0.2
  6  0  1    3.8    2.8     0 -7 -6    0.0    0.0     6 -2  1    2.2    3.1
  7  1  2    4.6    4.4     1 -6 -5    0.0    0.0     7 -1  2    2.4    1.7
  8  2  3    3.2    2.0     2 -5 -4   24.3   23.7     8  0  3    5.1    5.1
  0 -6 -6   21.2   21.6     3 -4 -3    4.0    4.1     1 -7 -5    3.8    3.6
  1 -5 -5   17.8   17.3     4 -3 -2    2.4    0.5     2 -6 -4   46.9   48.0
  2 -4 -4   14.3   14.1     5 -2 -1    9.1    9.4     3 -5 -3   23.0   22.4
  3 -3 -3    8.4    8.4     6 -1  0   28.4   28.6     4 -4 -2    5.8    6.2
  4 -2 -2   63.3   64.5     7  0  1    5.1    3.9     5 -3 -1   25.4   25.0
  5 -1 -1    3.0    5.3     8  1  2    0.0    0.5     6 -2  0   63.7   61.9
  6  0  0    4.8    4.0     1 -6 -6    9.1    9.3     7 -1  1    3.9    4.9
  7  1  1   27.4   25.8     2 -5 -5    0.0    0.7     8  0  2    2.0    0.8
  8  2  2   30.5   30.1     3 -4 -4   12.3   11.4     1 -7 -6    0.5    3.5
 -1 -8 -2    4.2    0.9     4 -3 -3    2.2    2.1     2 -6 -5    4.0    3.4
  0 -7 -1    4.7    4.0     5 -2 -2   30.7   30.3     3 -5 -4    3.7    3.5
  1 -6  0   27.8   28.4     6 -1 -1    9.6   10.9     4 -4 -3    0.0    1.8
  2 -5  1    9.6    9.6     7  0  0    9.4    9.9     5 -3 -2    2.1    3.0
  3 -4  2    0.0    0.2     8  1  1    9.8   10.6     6 -2 -1    1.4    0.6
  4 -3  3    3.9    4.0     9  2  2    9.6   13.1     7 -1  0    8.0    7.9
  
  
  H  K  L    FO     FC      H  K  L    FO     FC      H  K  L    FO     FC
  8  0  1    0.0    0.5     2 -7 -5    7.8    7.6     4 -6 -2   39.9   39.4
  9  1  2    3.4    1.9     3 -6 -4    6.3    7.0     5 -5 -1    6.7    6.4
  2 -6 -6    8.4    8.4     4 -5 -3   21.5   21.3     6 -4  0    8.9    9.2
  3 -5 -5    5.5    5.2     5 -4 -2   20.4   20.5     7 -3  1   10.1   10.0
  4 -4 -4   53.8   53.4     6 -3 -1    4.2    4.7     8 -2  2   30.7   32.7
  5 -3 -3   15.2   15.3     7 -2  0    7.9    8.2     3 -7 -4    7.6    8.0
  6 -2 -2    7.8    7.8     8 -1  1    0.0    3.6     4 -6 -3    8.3    9.0
  7 -1 -1   12.8   13.1     9  0  2   15.4   16.2     5 -5 -2    0.0    2.3
  8  0  0   30.7   35.4     2 -7 -6    4.8    4.5     6 -4 -1    9.9    9.1
  9  1  1   25.3   24.2     3 -6 -5    6.3    6.8     7 -3  0    7.8    8.2
  0 -9 -1    0.0    1.5     4 -5 -4    3.2    5.0     8 -2  1    4.9    4.1
  1 -8  0    5.6    3.5     5 -4 -3   13.5   12.9     9 -1  2    4.9    4.9
  2 -7  1    3.9    4.6     6 -3 -2   13.9   14.1     3 -7 -5   12.9   14.1
  3 -6  2   14.9   14.4     7 -2 -1    4.0    4.4     4 -6 -4    0.0    0.7
  4 -5  3   13.3   12.7     8 -1  0    5.1    4.2     5 -5 -3    3.0    4.0
  5 -4  4    5.2    4.7     9  0  1    4.7    1.1     6 -4 -2   36.9   37.6
  6 -3  5    7.9    7.1     3 -6 -6   21.2   22.6     7 -3 -1    4.5    0.6
  7 -2  6    0.0    4.1     4 -5 -5   19.1   19.5     8 -2  0    3.0    0.1
  0 -9 -2   13.5   16.5     5 -4 -4    9.5    8.8     9 -1  1   17.9   16.6
  1 -8 -1    6.3    4.2     6 -3 -3    3.1    4.3     4 -6 -5   11.7   12.5
  2 -7  0    8.6    8.8     7 -2 -2   42.3   38.7     5 -5 -4    4.7    0.6
  3 -6  1    3.9    4.5     8 -1 -1    3.4    5.2     6 -4 -3    2.3    1.4
  4 -5  2   20.3   20.6     9  0  0    7.8    9.0     7 -3 -2    6.9    6.2
  5 -4  3   22.2   21.4     1 -9  0    2.3    6.8     8 -2 -1   13.9   13.8
  6 -3  4    7.3    7.4     2 -8  1   12.2   13.7     9 -1  0    5.4    6.2
  7 -2  5    7.5    7.5     3 -7  2    3.5    6.5     4 -6 -6   21.2   23.3
  1 -8 -2    7.3    8.6     4 -6  3    2.9    1.8     5 -5 -5    0.0    4.0
  2 -7 -1    6.8    7.0     5 -5  4    0.7    0.3     6 -4 -4    5.2    5.6
  3 -6  0   11.0   10.5     6 -4  5   12.0   12.6     7 -3 -3    7.3    8.2
  4 -5  1    9.6    9.1     1 -9 -1   17.1   16.7     8 -2 -2   32.4   31.7
  5 -4  2   22.0   20.5     2 -8  0    4.2    0.7     9 -1 -1    8.2    8.7
  6 -3  3   12.9   12.9     3 -7  1    1.2    0.4     3 -8  2    5.7    5.3
  7 -2  4    0.0    0.5     4 -6  2   39.0   38.0     4 -7  3    5.9    5.4
  8 -1  5    6.2    4.7     5 -5  3    3.9    3.8     5 -6  4    9.8   10.3
  1 -8 -3    3.1    0.9     6 -4  4    0.8    0.5     6 -5  5    5.3    6.0
  2 -7 -2   19.2   18.7     7 -3  5   13.8   13.7     2 -9  0   17.5   19.2
  3 -6 -1    1.9    2.0     1 -9 -2    0.0    4.9     3 -8  1    7.7    8.5
  4 -5  0    2.5    2.0     2 -8 -1    5.3    3.2     4 -7  2   15.3   15.2
  5 -4  1   13.6   14.4     3 -7  0    7.9    7.7     5 -6  3    3.7    4.4
  6 -3  2   19.5   19.1     4 -6  1    9.7    9.6     6 -5  4   18.3   18.8
  7 -2  3   10.6   10.8     5 -5  2    3.2    2.8     7 -4  5   14.0   15.0
  8 -1  4    5.2    5.4     6 -4  3    8.3    8.4     2 -9 -1    6.5    6.2
  1 -8 -4    6.3    6.0     7 -3  4    7.7    8.1     3 -8  0   13.1   12.6
  2 -7 -3   10.1   10.3     2 -8 -2   34.6   32.8     4 -7  1    5.3    4.4
  3 -6 -2   19.9   19.1     3 -7 -1    9.5   10.2     5 -6  2    8.2    8.4
  4 -5 -1   14.7   14.3     4 -6  0    9.2    9.3     6 -5  3   15.0   15.8
  5 -4  0    2.6    2.3     5 -5  1    6.4    7.0     7 -4  4   11.3   10.5
  6 -3  1    0.7    1.6     6 -4  2   39.0   39.5     3 -8 -1    7.2    6.2
  7 -2  2   18.5   18.6     7 -3  3    8.4   10.2     4 -7  0    9.9    9.1
  8 -1  3    1.9    0.9     8 -2  4    4.1    5.2     5 -6  1    3.1    2.0
  1 -8 -5    1.5    4.7     2 -8 -3    8.0   10.0     6 -5  2   10.9   11.4
  2 -7 -4    0.0    0.6     3 -7 -2   10.7   10.4     7 -4  3   16.9   17.4
  3 -6 -3   12.2   12.6     4 -6 -1    6.7    6.7     8 -3  4    5.7    2.2
  4 -5 -2   20.8   20.3     5 -5  0    3.9    3.8     3 -8 -2    1.5    2.8
  5 -4 -1    8.7    9.6     6 -4  1    8.2    7.4     4 -7 -1    9.1    9.5
  6 -3  0   10.2   11.1     7 -3  2   10.3   10.2     5 -6  0   15.9   15.7
  7 -2  1    7.0    7.0     8 -2  3    8.0    9.3     6 -5  1    1.5    1.7
  8 -1  2    5.4    9.0     2 -8 -4    3.9    5.2     7 -4  2    6.6    7.1
  9  0  3   13.0   13.3     3 -7 -3    8.5   10.0     8 -3  3    0.0    1.6
  
  
  H  K  L    FO     FC      H  K  L    FO     FC      H  K  L    FO     FC
  3 -8 -3    0.0    1.3     9 -2  0   20.3   19.4     5 -7 -1    8.9    8.6
  4 -7 -2    6.4    7.5     5 -6 -5    6.0    5.6     6 -6  0   31.6   32.3
  5 -6 -1    0.0    1.6     6 -5 -4   10.6   10.2     7 -5  1    8.0    8.6
  6 -5  0   15.7   15.8     7 -4 -3    4.9    5.2     8 -4  2    4.4    4.3
  7 -4  1    8.6    9.6     8 -3 -2    6.2    5.7     4 -8 -3    0.0    0.5
  8 -3  2    4.7    3.3     9 -2 -1    0.0    0.5     5 -7 -2   12.9   13.8
  3 -8 -4    3.9    2.2     6 -5 -5    8.5    8.6     6 -6 -1    1.5    0.5
  4 -7 -3   17.7   17.9     7 -4 -4   15.1   15.4     7 -5  0   11.0   10.2
  5 -6 -2   11.1   11.2     8 -3 -3    8.1    9.5     8 -4  1    4.9    4.3
  6 -5 -1    1.5    1.7     4 -8  2    0.0    0.7     5 -7 -3    5.9    6.9
  7 -4  0    9.1    9.2     5 -7  3    9.3    9.5     6 -6 -2    2.6    4.8
  8 -3  1    5.8    6.2     4 -8  1    4.8    7.9     7 -5 -1    6.8    7.7
  9 -2  2   12.0    8.4     5 -7  2    0.0    1.5     8 -4  0   26.7   26.2
  4 -7 -4    9.8   10.7     6 -6  3    6.9    7.0     6 -6 -3    7.5    6.7
  5 -6 -3   15.4   15.5     4 -8  0   22.6   26.1     7 -5 -2    3.3    1.6
  6 -5 -2    9.1    9.1     5 -7  1    7.5    7.7     8 -4 -1    8.1    7.0
  7 -4 -1    3.4    4.1     6 -6  2    4.6    4.8     7 -5 -3    7.6    9.2
  8 -3  0   12.9   13.2     7 -5  3    6.2    6.9     8 -4 -2    3.9    0.5
  9 -2  1    6.3    5.6     4 -8 -1    5.2    4.9     6 -7  1    1.8    4.6
  4 -7 -5   12.3   14.9     5 -7  0   10.0   10.3     6 -7  0   11.1    9.9
  5 -6 -4   19.4   18.7     6 -6  1    0.0    0.2     7 -6  1    3.6    2.0
  6 -5 -3    4.2    4.2     7 -5  2   12.3   13.7     6 -7 -1    2.5    2.1
  7 -4 -2   14.5   15.4     8 -4  3    0.0    0.7     7 -6  0   10.9    9.6
  8 -3 -1    8.8    8.3     4 -8 -2    4.4    4.6     7 -6 -1    4.3    4.9