ABINIT Discussion Forums

Posted: **Tue Mar 08, 2011 9:42 pm**

I am trying to build a monoclinic cell of Ga2O3, with a =12.23, b=3.04, c=5.80, and beta=103.7. From the international tables, this belongs to space group #12, with 5-atoms specified, each of multiplicity 4, which results in a total of 20 atoms in the cell. Here is how I specified the input file:

spgroup 12
brvltt -1

acell 12.23 3.04 5.80 Angstroms # cell dimensions
angdeg 90 103.7 90 # monoclinic cell

natom 5 # 5 atoms
typat 2*1 3*2 # 2 Ga atoms, and 3 O atoms
xred
0.34 0.00 0.69
0.09 0.00 0.79
0.17 0.00 0.10
0.50 0.00 0.26
0.83 0.00 0.44

However I got a runtime error that comes from "symatm.F90", shown below. Does anyone have a clue of where I might be wrong? Thanks a lot for your help.

Renyu

Trouble finding symmetrically equivalent atoms
Applying inv of symm number 2 to atom number 1 of typat 1
gives tratom= -3.4000E-01 3.4000E-01 -6.9000E-01.
This is further away from every atom in crystal than the allowed tolerance.
The inverse symmetry matrix is 0 1 0
1 0 0
0 0 -1
and the nonsymmorphic transl. tnons = 0.0000000 0.0000000 0.0000000
The nearest coordinate differs by 3.200E-01 -3.200E-01 -3.800E-01
for indsym(nearest atom)= 1
At line 183 of file ../../../src/42_geometry/symatm.F90
Fortran runtime error: End of file

Posted: **Tue Mar 08, 2011 11:22 pm**

Hi Renyu,

Similar discussion as in http://forum.abinit.org/viewtopic.php?f=8&t=843&start=0 Try brvlatt=0 to avoid conventional/primitive cell gymnastics

Code: Select all

...
acell 12.23 3.04 5.80 angstroms
spgroup 12
angdeg 90 103.83 90
ntypat 2
znucl 31 8
natom 20
natrd 5
typat 1 1 2 2 2
chkprim 0
brvltt 0
xred
0.34 0.00 0.69
0.09 0.00 0.79
0.17 0.00 0.10
0.50 0.00 0.26
0.83 0.00 0.44
ecut 8.0
kptopt 0
nkpt 1
nline 1
nstep 1
toldfe 1.0d-6
prtcif 1

Kind regards,

Alain

P.S. can you show me your complete input? Even if they are errors, it should not crash

Posted: **Wed Mar 09, 2011 2:29 am**

Hi Alain,

Thanks a lot for your reply! Now it works. I also tried brvlatt=-1 and natom=10 and it gives me the primitive cell. So I guess for generating conventional cells we should use brvlatt=0 and natom=<total # atoms in conventional cell> and for primitive cells we should use brvlatt=-1 with natom=<total # atoms in primitive cell>. In both cases, natrd should be exactly the same as the number of entries in xred. Am I right? I also attached the full input file for your reference.

You are really helpful. Thanks again for your help.

Renyu

Code: Select all

chksymbreak 0

spgroup 12
brvltt -1

ntypat 2
znucl 31 8
acell   12.23  3.04  5.80 Angstroms
angdeg  90 103.7 90
natom 5
typat 2*1 3*2
xred
  0.34  0.00  0.69
  0.09  0.00  0.79
    0.17  0.00  0.10
    0.50  0.00  0.26
    0.83  0.00  0.44

ecut 8.0
nstep 100
toldfe  1.0d-6
diemac 12.0
kptopt 0
nkpt 1

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