[Pw_forum] Conserving the same Wyckoff multiplicity in the input and in the output
hqtst42
hqtst42 at netc.pl
Wed Apr 12 12:03:47 CEST 2017
Hi Paolo,
Many thanks for your reply ; maybe the problem may be something
different ; I see a symmetry break from the gipaw simulation. Because of
the symmetry, I expect, for example, 4 carbons with identical chemical
shifts, yet I have 2 pairs of 2 equivalent carbon instead. For example:
-------------------------------------------------------------------------------------------
Total NMR chemical shifts in ppm:
---------------------------------------
(adopting the Simpson convention for anisotropy and
asymmetry)-----------
Atom 1 C pos: ( 0.702166 0.334168 0.055776) Total
sigma: 154.68
95.6267 39.1235 -16.2688
45.6199 165.6715 -100.3341
-21.3569 -108.3456 202.7526
C 1 anisotropy: 216.17 eta: -0.2840
C 1 sigma_11= 103.0939 axis=( 0.761900 0.370231 0.531448)
C 1 sigma_22= 62.1589 axis=( 0.615219 -0.670233 -0.415082)
C 1 sigma_33= 298.7979 axis=( -0.202517 -0.643208 0.738424)
Atom 2 C pos: ( 0.297834 0.203502 0.675798) Total
sigma: 154.68
95.6267 39.1235 -16.2688
45.6199 165.6715 -100.3341
-21.3569 -108.3456 202.7526
C 2 anisotropy: 216.17 eta: -0.2840
C 2 sigma_11= 103.0939 axis=( 0.761900 0.370231 0.531448)
C 2 sigma_22= 62.1589 axis=( 0.615219 -0.670233 -0.415082)
C 2 sigma_33= 298.7979 axis=( -0.202517 -0.643208 0.738424)
Atom 3 C pos: ( 0.297163 0.472864 0.419799) Total
sigma: 155.11
95.2156 39.0348 15.4560
45.5222 166.0586 99.6009
19.2085 107.7438 204.0451
C 3 anisotropy: 215.17 eta: -0.2971
C 3 sigma_11= 104.6936 axis=( -0.750294 -0.387720 0.535474)
C 3 sigma_22= 62.0730 axis=( -0.631164 0.661092 -0.405696)
C 3 sigma_33= 298.5528 axis=( 0.196701 0.642363 0.740729)
Atom 4 C pos: ( 0.702837 0.064806 0.311775) Total
sigma: 155.11
95.2156 39.0348 15.4560
45.5222 166.0586 99.6009
19.2085 107.7438 204.0451
C 4 anisotropy: 215.17 eta: -0.2971
C 4 sigma_11= 104.6936 axis=( -0.750294 -0.387720 0.535474)
C 4 sigma_22= 62.0730 axis=( -0.631164 0.661092 -0.405696)
C 4 sigma_33= 298.5528 axis=( 0.196701 0.642363 0.740729)
-------------------------------------------------------------------------------------------
There is apparently no version number for
GIPAW:
-------------------------------------------------------------------------------------------
Program QE v.6.0 (svn rev. 13079) starts on 16Mar2017 at 19:27:28
***** This is GIPAW svn revision unknown *****
-------------------------------------------------------------------------------------------
Many thanks again for your time.
Henri Colaux
Le 2017/04/05 à 15:31, Paolo Giannozzi a écrit :
> This is what you get:
> 2 Sym. Ops., with inversion, found
> (note: 2 additional sym.ops. were found but ignored
> their fractional translations are incommensurate with FFT grid)
> and this is what you get if you specify "use_all_frac=.true.":
> 4 Sym. Ops., with inversion, found ( 2 have fractional translation)
> These are symmetry operations (visible with verbosity='high')
> s frac. trans.
>
> isym = 1 identity
>
> cryst. s( 1) = ( 1 0 0 )
> ( 0 1 0 )
> ( 0 0 1 )
>
> cart. s( 1) = ( 1.0000000 0.0000000 0.0000000 )
> ( 0.0000000 1.0000000 0.0000000 )
> ( 0.0000000 0.0000000 1.0000000 )
>
>
> isym = 2 180 deg rotation - cart. axis [0,0,1]
>
> cryst. s( 2) = ( -1 0 0 ) f =( 0.0000000 )
> ( 0 -1 0 ) ( 0.5000000 )
> ( 0 0 1 ) ( 0.5000000 )
>
> cart. s( 2) = ( -1.0000000 0.0000000 0.0000000 ) f =( 0.0000000 )
> ( 0.0000000 -1.0000000 0.0000000 ) ( 0.2688348 )
> ( 0.0000000 0.0000000 1.0000000 ) ( 0.3657871 )
>
>
> isym = 3 inversion
>
> cryst. s( 3) = ( -1 0 0 )
> ( 0 -1 0 )
> ( 0 0 -1 )
>
> cart. s( 3) = ( -1.0000000 0.0000000 0.0000000 )
> ( 0.0000000 -1.0000000 0.0000000 )
> ( 0.0000000 0.0000000 -1.0000000 )
>
>
> isym = 4 inv. 180 deg rotation - cart. axis [0,0,1]
>
> cryst. s( 4) = ( 1 0 0 ) f =( 0.0000000 )
> ( 0 1 0 ) ( 0.5000000 )
> ( 0 0 -1 ) ( 0.5000000 )
>
> cart. s( 4) = ( 1.0000000 0.0000000 0.0000000 ) f =( 0.0000000 )
> ( 0.0000000 1.0000000 0.0000000 ) ( 0.2688348 )
> ( 0.0000000 0.0000000 -1.0000000 ) ( 0.3657871 )
>
>
> point group C_2h (2/m)
> there are 4 classes
> the character table:
>
> E C2 i s_h
> A_g 1.00 1.00 1.00 1.00
> B_g 1.00 -1.00 1.00 -1.00
> A_u 1.00 1.00 -1.00 -1.00
> B_u 1.00 -1.00 -1.00 1.00
>
> the symmetry operations in each class and the name of the first element:
>
> E 1
> identity
> C2 2
> 180 deg rotation - cart. axis [0,0,1]
> i 3
> inversion
> s_h 4
> inv. 180 deg rotation - cart. axis [0,0,1]
>
> On Wed, Apr 5, 2017 at 7:51 AM, Paolo Giannozzi <p.giannozzi at gmail.com> wrote:
>> Structural optimization doesn't break the symmetry. The final symmetry
>> - the one found by the code, I mean - should be the same as the
>> initial one.
>>
>> On Wed, Apr 5, 2017 at 2:46 AM, hqtst42 <hqtst42 at netc.pl> wrote:
>>> In the input file, there are the atomic coordinates for only one
>>> molecule, and with the symmetry operation, I expect 4 equivalent
>>> molecules per unit cell. Yet, the structure optimisation results in 2
>>> pairs of 2 equivalent molecules per unit cell. I would like to explain
>>> to the program not to break the symmetry.
>>>
>>> Le 2017/04/04 à 21:45, Paolo Giannozzi a écrit :
>>>> What do you mean by "results with multiplicity 1" and "Wyckoff multiplicity?
>>>>
>>>> On Tue, Apr 4, 2017 at 12:08 PM, hqtst42 <hqtst42 at netc.pl> wrote:
>>>>> Dear everyone,
>>>>>
>>>>> In the enclosed input file, I set atomic coordinates of all equivalent atoms
>>>>> with crystal_sg and the space group.
>>>>>
>>>>> This should give results with a multiplicity of 1, but I have instead a
>>>>> multiplicity of 2 in the output file.
>>>>> How can I force the program to conserve the Wyckoff multiplicity taken as an
>>>>> input ?
>>>>> All in QE v 6.0
>>>>>
>>>>> Many thanks in advance,
>>>>>
>>>>> Henri Colaux
>>>>> Research associate
>>>>> RIKEN Yokohama
>>>>>
>>>>> _______________________________________________
>>>>> Pw_forum mailing list
>>>>> Pw_forum at pwscf.org
>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>
>>>
>>> _______________________________________________
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
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>>
>>
>> --
>> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
>> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>> Phone +39-0432-558216, fax +39-0432-558222
>
>
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