findprim.f90 and findsymcrystr.f90 changed??
Status: Beta
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Two Concerns:
1. Correct me if I am wrong but as per my understanding it is claimed that the fractional atomic coordinates that are printed out in the INFO.OUT file are those of the Primitive cell. I think that might not be the case.
Moreover the fractional coordinates that were printed out by an earlier version of the program are different. And both of them do not corrsepond to the fractional coordinates of the Primitive cell. An Example is given below.
2. Also for no change in fractional coordinates, the reduced number of k-points is also found to be changed. This is because of a change in number of crystal symmetries.
I will now give examples to substantiate my claim.
Example 1: Hafnium Silicate (In this case both the Old and the New versions of EXCITING failed to reproduce the fractional atomic coordinates in the Primitive lattice which was the input and is reproduced below:
Hf: 2
0.8750000000000000 0.1250000000000000 0.7500000000000000
0.1250000000000000 0.8750000000000000 0.2500000000000000
Si: 2
0.6250000000000000 0.3750000000000000 0.2500000000000000
0.3750000000000000 0.6250000000000000 0.7500000000000000
O: 8
0.2603000000000000 0.1948000000000000 0.0655000000000000
0.1948000000000000 0.6293000000000000 0.9345000000000000
0.1948000000000000 0.2603000000000000 0.5655000000000000
0.7397000000000000 0.8052000000000000 0.9345000000000000
0.8052000000000000 0.3707000000000000 0.0655000000000000
0.8052000000000000 0.7397000000000000 0.4345000000000000
0.6293000000000000 0.1948000000000000 0.4345000000000000
0.3707000000000000 0.8052000000000000 0.5655000000000000
------------------------------------------------------
FILE 1: Older version (From INFO.OUT)
------------------------------------------------------
Species : 1, Hf
parameters loaded from : Hf.in
name : hafnium
nuclear charge : -72.00000000
electronic charge : 72.00000000
atomic mass : 325367.3657
muffin-tin radius : 1.893100000
number of radial points in muffin-tin : 629
atomic position (lattice), magnetic field (Cartesian) :
1 1.00000000 1.00000000 1.00000000 0.00000000 0.00000000 0.00000000
2 0.25000000 1.75000000 0.50000000 0.00000000 0.00000000 0.00000000
Species : 2, Si
parameters loaded from : Si.in
name : silicon
nuclear charge : -14.00000000
electronic charge : 14.00000000
atomic mass : 51196.73454
muffin-tin radius : 1.487100000
number of radial points in muffin-tin : 357
atomic position (lattice), magnetic field (Cartesian) :
1 0.75000000 1.25000000 0.50000000 0.00000000 0.00000000 0.00000000
2 0.50000000 1.50000000 1.00000000 0.00000000 0.00000000 0.00000000
Species : 3, O
parameters loaded from : O.in
name : oxygen
nuclear charge : -8.000000000
electronic charge : 8.000000000
atomic mass : 29165.12203
muffin-tin radius : 1.391900000
number of radial points in muffin-tin : 269
atomic position (lattice), magnetic field (Cartesian) :
1 0.38275501 1.06824570 0.31450931 0.00000000 0.00000000 0.00000000
2 0.31824570 1.50373639 1.18549069 0.00000000 0.00000000 0.00000000
3 0.31824570 1.13275501 0.81450931 0.00000000 0.00000000 0.00000000
4 0.86724499 1.68175430 1.18549069 0.00000000 0.00000000 0.00000000
5 0.93175430 1.24626361 0.31450931 0.00000000 0.00000000 0.00000000
6 0.93175430 1.61724499 0.68549069 0.00000000 0.00000000 0.00000000
7 0.75373639 1.06824570 0.68549069 0.00000000 0.00000000 0.00000000
8 0.49626361 1.68175430 0.81450931 0.00000000 0.00000000 0.00000000
Total number of atoms per unit cell : 12
Spin treatment :
spin-unpolarised
Number of Bravais lattice symmetries : 16
Number of crystal symmetries : 8
Inversion symmetry does not exist
k-point grid : 14 14 14
k-point offset : 0.000000000 0.000000000 0.000000000
k-point set is reduced with crystal symmetries
Total number of k-points : 403
---------------------------------------------------------------------
File 2: Newer Version
---------------------------------------------------------------------
Species : 1 (Hf)
parameters loaded from : Hf.in
name : hafnium
nuclear charge : -72.00000000
electronic charge : 72.00000000
atomic mass : 325367.3657
muffin-tin radius : 1.893100000
number of radial points in muffin-tin : 629
atomic position (lattice), magnetic field (Cartesian) :
1 0.61724499 -0.06824570 0.68549069 0.00000000 0.00000000 0.00000000
2 -0.13275501 0.68175430 0.18549069 0.00000000 0.00000000 0.00000000
Species : 2 (Si)
parameters loaded from : Si.in
name : silicon
nuclear charge : -14.00000000
electronic charge : 14.00000000
atomic mass : 51196.73454
muffin-tin radius : 1.487100000
number of radial points in muffin-tin : 357
atomic position (lattice), magnetic field (Cartesian) :
1 0.36724499 0.18175430 0.18549069 0.00000000 0.00000000 0.00000000
2 0.11724499 0.43175430 0.68549069 0.00000000 0.00000000 0.00000000
Species : 3 (O)
parameters loaded from : O.in
name : oxygen
nuclear charge : -8.000000000
electronic charge : 8.000000000
atomic mass : 29165.12203
muffin-tin radius : 1.391900000
number of radial points in muffin-tin : 269
atomic position (lattice), magnetic field (Cartesian) :
1 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000
2 -0.06450931 0.43549069 0.87098138 0.00000000 0.00000000 0.00000000
3 -0.06450931 0.06450931 0.50000000 0.00000000 0.00000000 0.00000000
4 0.48448998 0.61350860 0.87098138 0.00000000 0.00000000 0.00000000
5 0.54899929 0.17801791 0.00000000 0.00000000 0.00000000 0.00000000
6 0.54899929 0.54899929 0.37098138 0.00000000 0.00000000 0.00000000
7 0.37098138 0.00000000 0.37098138 0.00000000 0.00000000 0.00000000
8 0.11350860 0.61350860 0.50000000 0.00000000 0.00000000 0.00000000
Total number of atoms per unit cell : 12
Spin treatment :
spin-unpolarised
Number of Bravais lattice symmetries : 16
Number of crystal symmetries : 2
k-point grid : 12 12 12
k-point offset : 0.000000000 0.000000000 0.000000000
k-point set is reduced with crystal symmetries
Total number of k-points : 936
---------------------------------------------------------------------------------------------
Notice the change in fractional coordinates and number of crystal symmetries
Example 2: Zirconium Oxide: (please notice the change in k-points)
------------------------------------------------------
FILE 1: Older version
------------------------------------------------------
Unit cell volume : 432.2811316
Brillouin zone volume : 0.5738168875
Species : 1, Zr
parameters loaded from : Zr.in
name : zirconium
nuclear charge : -40.00000000
electronic charge : 40.00000000
atomic mass : 166291.1791
muffin-tin radius : 2.000000000
number of radial points in muffin-tin : 537
atomic position (lattice), magnetic field (Cartesian) :
1 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000
2 0.50000000 0.50000000 0.50000000 0.00000000 0.00000000 0.00000000
Species : 2, O
parameters loaded from : O.in
name : oxygen
nuclear charge : -8.000000000
electronic charge : 8.000000000
atomic mass : 29165.12203
muffin-tin radius : 1.450000000
number of radial points in muffin-tin : 269
atomic position (lattice), magnetic field (Cartesian) :
1 0.00000000 0.50000000 0.28239753 0.00000000 0.00000000 0.00000000
2 0.00000000 0.50000000 0.78239753 0.00000000 0.00000000 0.00000000
3 0.50000000 0.00000000 0.21760247 0.00000000 0.00000000 0.00000000
4 0.50000000 0.00000000 0.71760247 0.00000000 0.00000000 0.00000000
Total number of atoms per unit cell : 6
Spin treatment :
spin-unpolarised
Number of Bravais lattice symmetries : 16
Number of crystal symmetries : 8
Inversion symmetry does not exist
k-point grid : 12 12 12
k-point offset : 0.000000000 0.000000000 0.000000000
k-point set is reduced with crystal symmetries
Total number of k-points : 301
---------------------------------------------------------------------
File 2: Newer Version
---------------------------------------------------------------------
Species : 1 (Zr)
parameters loaded from : Zr.in
name : zirconium
nuclear charge : -40.00000000
electronic charge : 40.00000000
atomic mass : 166291.1791
muffin-tin radius : 2.000000000
number of radial points in muffin-tin : 537
atomic position (lattice), magnetic field (Cartesian) :
1 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000
2 0.50000000 0.50000000 0.50000000 0.00000000 0.00000000 0.00000000
Species : 2 (O)
parameters loaded from : O.in
name : oxygen
nuclear charge : -8.000000000
electronic charge : 8.000000000
atomic mass : 29165.12203
muffin-tin radius : 1.450000000
number of radial points in muffin-tin : 269
atomic position (lattice), magnetic field (Cartesian) :
1 0.00000000 0.50000000 0.28239753 0.00000000 0.00000000 0.00000000
2 0.00000000 0.50000000 0.78239753 0.00000000 0.00000000 0.00000000
3 0.50000000 0.00000000 0.21760247 0.00000000 0.00000000 0.00000000
4 0.50000000 0.00000000 0.71760247 0.00000000 0.00000000 0.00000000
Total number of atoms per unit cell : 6
Spin treatment :
spin-unpolarised
Number of Bravais lattice symmetries : 16
Number of crystal symmetries : 16
k-point grid : 12 12 12
k-point offset : 0.000000000 0.000000000 0.000000000
k-point set is reduced with crystal symmetries
Total number of k-points : 196
-------------------------------------------------------------------------------------
Thanks for the careful testing.
The new version doesn't shift the crystal to the optimal center. This is because the crystal symmetries are now the full space group operations, as opposed to just the point group operations in the older version.
As there are now more symmetries, the k-point set can be reduced more than it was in the past. This should not affect the results though, it just makes the code more efficient.
Regards,
Kay.
Dear Ravi,
You were right about the problem. This has been now fixed in version 0.9.93.
I've also added HfSiO4 to the examples directory.
Thanks again,
Kay.
Perhaps I am overlooking something obvious, but I fear there may still be a problem even in 0.9.93.
For my current test case, CaGe (spacegroup Cmcm, 8.648x20.501x7.563), I find that the fractional coordinates given in
INFO.OUT are shifted to place the first atom in the list at the origin:
exciting.in (using conventional cell):
'Ca.in'
4
0.000 0.362 0.250 0. 0. 0.
0.500 0.862 0.250 0. 0. 0.
0.000 0.638 0.750 0. 0. 0.
0.500 0.138 0.750 0. 0. 0.
and INFO.OUT:
1 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
2 0.5000 0.5000 0.0000 0.0000 0.0000 0.0000
3 0.0000 0.2760 0.5000 0.0000 0.0000 0.0000
4 0.5000 0.7760 0.5000 0.0000 0.0000 0.0000
(and accordingly for the Ge site). In versions up to 0.9.74, the coordinate list in INFO.OUT matched the input.
Martin
(BTW, the newly added HfSiO4 example needs to have its sppath adjusted)
Hi Martin,
EXCITING (0.9.93) shifts the basis so that the first atom in the smallest atom set is at the origin. This is to ensure that a maximum number of symmetry operations are found.
You can switch shifting off with
tshift
.false.
Versions of the code after 0.9.74 have a new (and sophisticated) way of handling symmetry, which is why there have been so many symmetry-related bugs of late.
Thanks for letting me know about the sppath variable in HfSiO4.
Cheers,
Kay.