# [Pw_forum] How should I input the positions of atoms for such material?

lyw1983 lyw1983 at 163.com
Thu Apr 27 14:33:22 CEST 2006

```Dear all:
The structure of the Ga2o3 is Monoclinic base-centered, and with
a spacegroup of number12, so the primitive cell of it is not the
unit cell, for this material, we should input celldm(1)=a,
celldm(2)=b/a,celldm(3)=c/a and celldm(4)=cos(ab),but the angle between a and b is 90o, and the angle between a and c is 103.7o,
so we should change the axis as follow: a changes to b, b change
to c and c change to a, now the angle between a and b is 103.7o,
but when I input the positions of atoms, how should I change the
positions?
the iformation of Ga2O3 as below:a=12.23Å, b=3.04Å, c=5.80Å, α=90o,
β=103.7o, γ=90o, the positions of atoms in primitive cell are:
Ga    0.09040   0.09040   0.79480
Ga    0.34140   0.34140   0.68570
O     0.16740   0.16740   0.10110
O     0.49570   0.49570   0.25530
O     0.82790   0.82790   0.43650
Ga    0.90960   0.90960   0.20520
Ga    0.65860   0.65860   0.31430
O     0.83260   0.83260   0.89890
O     0.50430   0.50430   0.74470
O     0.17210   0.17210   0.56350
Perhaps this question is very stupid, but it really puzzled me for a
long time, so I really need your help!
Thanks very much!

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