Institute of Experimental Mineralogy
                 Russian Academy of Sciences
     -------------------------------------------------
           142432, Chernogolovka, Moscow district
             A.V. Chichagov  +7(496)52-22320

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WESTERVELDITE

2, syn, at 0.0001 GPa, f-nickeline, g-modderite

FeAs


Orthorhombic  P nam  Z = 4

Pnam

6 .8 .1907

Ref.Str.:

         Lyman P.S., Prewitt C.T. (1984)

         * Acta Cryst., B40, 14-20

Reserv:

         All structure data for this sample at pressures from 0.0001 GPa

         upto 8.3 GPa see in the original. N.A.D.

                   Initial data from BDM-file 

   Lattice parameters (cub. angs.,degr.):

             a =   5.4401   alpha =   90.0 
             b =   6.0259   beta  =   90.0 
             c =   3.3712   gamma =   90.0 

    Unit cell volume (cub. angs.) =   110.51

    Molar volume ( cub.cm/mol.) =    16.64

  Co-ordinates, thermal parameters, occupation for atomic positions:

NoP   x/a     y/b     z/c    B(j)   atom  / occupation

   1 0.0033  0.1993  0.25     0.0    Fe    = 1.00
   2 0.1992  0.5773  0.25     0.0    As    = 1.00


  Co-ordinates for all atomic positions :

   No       NoP      x/a        y/b       z/c 

     1       1     0.0033     0.1993     0.25  
     2       2     0.1992     0.5773     0.25  
     3       1     0.9967     0.8007     0.75  
     4       2     0.8008     0.4227     0.75  
     5       1     0.5033     0.3007     0.25  
     6       2     0.6992     0.9227     0.25  
     7       1     0.4967     0.6993     0.75  
     8       2     0.3008     0.0773     0.75  


X-ray density (g/cm cub.)   =      7.86

MU (1/cm) =     753.37     Mass attenuation coefficient (cm**2/g) =     95.885

 Selected interatomic distances (cation-anion,anion-anion):

 NoP    Atom              Rad.sph.      C.N.    Distance     NoP N.
                           (angs.)               (angs.)

    1    Fe                  3.252        6
                                                 2.5148       2
                                                 2.4222       2
                                                 2.4222       2
                                                 2.3484       2
                                                 2.4497       2
                                                 2.4497       2
    2    As                  4.584       12
                                                 3.3712       2
                                                 3.3712       2
                                                 3.7974       2
                                                 3.7974       2
                                                 2.8994       2
                                                 2.8994       2
                                                 3.425        2
                                                 3.425        2
                                                 3.4964       2
                                                 3.4964       2
                                                 3.4964       2
                                                 3.4964       2

  X-ray diffraction powder data (II),  X-Ray W.L. =   1.78892(angs.):

  No   H   K   L   Theta 2*Theta    S       LPG   MF        F          I int.
                    ( degree )                                         *100

    1   1   1   0 12.798  25.596   0.124   37.9     4        4.2       21.4
    2   0   2   0 17.27   34.54    0.166   19.94    2        6.0       11.7
    3   0   1   1 17.699  35.399   0.17    18.9     4       28.9      517.1
    4   2   0   0 19.198  38.397   0.184   15.81    2        3.9        4.0
    5   1   2   0 19.838  39.676   0.19    14.7     4       84.5     3437.9
    6   1   1   1 20.221  40.441   0.193   14.09    8       88.4     7216.8
    7   2   1   0 21.149  42.297   0.202   12.74    4       26.0      281.1
    8   2   0   1 24.994  49.989   0.236    8.73    4       62.4     1113.8
    9   1   2   1 25.516  51.033   0.241    8.33    8       70.0     2675.7
   10   2   2   0 26.297  52.594   0.248    7.78    4      103.6     2733.9
   11   2   1   1 26.606  53.211   0.25     7.58    8      106.2     5597.4
   12   1   3   0 28.339  56.679   0.265    6.56    4       61.7      819.1
   13   3   1   0 31.005  62.01    0.288    5.37    4       88.3     1370.6
   14   2   2   1 31.091  62.182   0.289    5.33    8       28.8      289.4
   15   0   3   1 31.222  62.444   0.29     5.28    4      131.1     2972.9
   16   0   0   2 32.049  64.098   0.297    4.99    2      158.8     2060.4
   17   1   3   1 32.943  65.887   0.304    4.7     8       10.9       36.4
   18   2   3   0 33.612  67.224   0.309    4.51    4       54.7      441.9
   19   1   1   2 35.101  70.203   0.321    4.12    8        4.4        5.1
   20   3   2   0 35.149  70.298   0.322    4.11    4       39.5      210.5
   21   3   1   1 35.41   70.82    0.324    4.05    8       46.0      561.7
   22   0   4   0 36.423  72.846   0.332    3.83    2       13.2       10.9
   23   0   2   2 37.448  74.897   0.34     3.64    4        1.4        0.2
   24   2   3   1 37.87   75.739   0.343    3.57    8       32.7      250.1
   25   1   4   0 38.031  76.062   0.344    3.54    4       74.4      641.1
   26   2   0   2 38.629  77.258   0.349    3.44    4        7.2        5.9
   27   1   2   2 39.042  78.083   0.352    3.38    8       67.0      995.4
   28   3   2   1 39.339  78.678   0.354    3.34    8       21.0       96.8
   29   2   1   2 39.917  79.835   0.359    3.27    8       20.9       93.7
   30   4   0   0 41.123  82.246   0.368    3.12    2       82.6      349.5
   31   3   3   0 41.646  83.293   0.371    3.07    4       40.0      161.1
   32   1   4   1 42.128  84.256   0.375    3.03    8       31.6      198.0
   33   4   1   0 42.394  84.787   0.377    3.0     4       41.0      165.3
   34   2   4   0 42.744  85.488   0.379    2.97    4       40.5      160.1
   35   2   2   2 43.731  87.462   0.386    2.9     8       82.1     1280.4


  X-ray diffraction powder data (I)...X-Ray wave length =  1.78892 (angs.):

  No   H   K   L   Theta 2*Theta    d           I int   I int.n.  I p.h.n.   H(Si)
                    ( degree )   (angstrem)     *100                         *100

    1   0   1   1  17.699  35.399  2.94208      517.1      7.2      7.2     5.7
    2   1   2   0  19.838  39.676  2.63571     3437.9     47.6     47.7     5.7
    3   1   1   1  20.221  40.441  2.58787     7216.8    100.0    100.0     5.7
    4   2   1   0  21.149  42.297  2.47918      281.1      3.9      3.9     5.7
    5   2   0   1  24.994  49.989  2.11691     1113.8     15.4     15.3     5.7
    6   1   2   1  25.516  51.033  2.07642     2675.7     37.1     36.6     5.8
    7   2   2   0  26.297  52.594  2.019       2733.9     37.9     37.4     5.8
    8   2   1   1  26.606  53.211  1.99725     5597.4     77.6     76.4     5.8
    9   1   3   0  28.339  56.679  1.88429      819.1     11.4     11.1     5.8
   10   3   1   0  31.005  62.01   1.73645     1370.6     19.0     18.5     5.8
   11   2   2   1  31.091  62.182  1.73212      289.4      4.0      3.9     5.8
   12   0   3   1  31.222  62.444  1.72556     2972.9     41.2     40.1     5.8
   13   0   0   2  32.049  64.098  1.6856      2060.4     28.6     27.7     5.9
   14   2   3   0  33.612  67.224  1.61582      441.9      6.1      5.9     5.9
   15   3   2   0  35.149  70.298  1.55367      210.5      2.9      2.8     5.9
   16   3   1   1  35.41   70.82   1.5437       561.7      7.8      7.5     5.9
   17   2   3   1  37.87   75.739  1.45709      250.1      3.5      3.3     6.0
   18   1   4   0  38.031  76.062  1.45184      641.1      8.9      8.4     6.0
   19   1   2   2  39.042  78.083  1.42004      995.4     13.8     13.0     6.0
   20   3   2   1  39.339  78.678  1.41103       96.8      1.3      1.3     6.0
   21   2   1   2  39.917  79.835  1.39393       93.7      1.3      1.2     6.0
   22   4   0   0  41.123  82.246  1.36003      349.5      4.8      4.5     6.1
   23   3   3   0  41.646  83.293  1.346        161.1      2.2      2.1     6.1
   24   1   4   1  42.128  84.256  1.33344      198.0      2.7      2.6     6.1
   25   4   1   0  42.394  84.787  1.32666      165.3      2.3      2.1     6.1
   26   2   4   0  42.744  85.488  1.31785      160.1      2.2      2.1     6.1
   27   2   2   2  43.731  87.462  1.29394     1280.4     17.7     16.4     6.2

Reference:
Chichagov A.V. et al.
Information-Calculating System on Crystal Structure Data of Minerals
(MINCRYST)
- Kristallographiya, v.35, n.3, 1990, p.610-616 (in Russian)