One problem of bands.x related to band representation
I observed that sometimes bands.x
cannot identify a proper band representation.
One example material is GaAs scf.in, scf.out.
If I run bands.x
calculation, I obtain almost good results (bands.out) except along the high-symmetry line connecting Gamma and L as shown in the excerpt below.
I searched the mailing list and found this answer. Following the suggestions there, I tried to increase ecutrho
, ecutwfc
, k-points and recheck the structure. But I always got the same result. Even though I change the pseudopotentials to ultrasoft or oncv, the result is still same. The nscf input nscf.in and output nscf.out are also attached.
So could you give an advice how can I obtain properly classified bands?
I checked that this happens at least for QE 6.6 and 6.7MaX with fix #277 (comment 496101987).
Minkyu Park
University of Ulsan, Republic of Korea
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xk=( 0.01852, 0.01852, 0.01852 )
double point group C_3v (3m)
there are 6 classes and 3 irreducible representations
the character table:
E -E 2C3 -2C3 3s_v -3s_v
G_4 2.00 -2.00 1.00 -1.00 0.00 0.00
G_5 1.00 -1.00 -1.00 1.00 0.00 0.00
G_6 1.00 -1.00 -1.00 1.00 0.00 0.00
imaginary part
E -E 2C3 -2C3 3s_v -3s_v
G_4 0.00 0.00 0.00 0.00 0.00 0.00
G_5 0.00 0.00 0.00 0.00 1.00 -1.00
G_6 0.00 0.00 0.00 0.00 -1.00 1.00
the symmetry operations in each class and the name of the first element:
E 1
-E -1
2C3 2 3
-2C3 -2 -3
3s_v 4 5 -6
3s_v 6 -4 -5
Band symmetry, C_3v (3m) double point group:
e( 1 - 1) = -8.93951 eV 1 --> ?
e( 2 - 3) = -8.93929 eV 2 --> G_4 L_6
e( 4 - 4) = -8.93893 eV 1 --> ?
e( 5 - 6) = -8.49722 eV 2 --> G_4 L_6
e( 7 - 7) = -8.45362 eV 1 --> ?
e( 8 - 9) = -8.45343 eV 2 --> G_4 L_6
e( 10 - 10) = -8.45297 eV 1 --> ?
e( 11 - 12) = -6.26258 eV 2 --> G_4 L_6
e( 13 - 14) = 5.79173 eV 2 --> G_4 L_6
e( 15 - 16) = 6.04524 eV 2 --> G_4 L_6
e( 17 - 17) = 6.19444 eV 1 --> ?
e( 18 - 18) = 6.19500 eV 1 --> ?
e( 19 - 20) = 6.47459 eV 2 --> G_4 L_6
e( 21 - 22) = 9.69270 eV 2 --> G_4 L_6
e( 23 - 24) = 9.87890 eV 2 --> G_4 L_6
e( 25 - 25) = 9.88305 eV 1 --> ?
e( 26 - 26) = 9.88318 eV 1 --> ?
e( 27 - 28) = 13.63031 eV 2 --> G_4 L_6
e( 29 - 29) = 16.06856 eV 1 --> ?
e( 30 - 31) = 16.07118 eV 2 --> G_4 L_6
e( 32 - 32) = 16.07424 eV 1 --> ?
e( 33 - 34) = 17.61511 eV 2 --> G_4 L_6
e( 35 - 36) = 17.68824 eV 2 --> G_4 L_6
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xk=( 0.03704, 0.03704, 0.03704 )
Band symmetry, C_3v (3m) double point group:
e( 1 - 1) = -8.93976 eV 1 --> ?
e( 2 - 3) = -8.93944 eV 2 --> G_4 L_6
e( 4 - 4) = -8.93860 eV 1 --> ?
e( 5 - 6) = -8.49733 eV 2 --> G_4 L_6
e( 7 - 7) = -8.45379 eV 1 --> ?
e( 8 - 9) = -8.45369 eV 2 --> G_4 L_6
e( 10 - 10) = -8.45250 eV 1 --> ?
e( 11 - 12) = -6.25131 eV 2 --> G_4 L_6
e( 13 - 14) = 5.55231 eV 2 --> G_4 L_6
e( 15 - 16) = 5.98130 eV 2 --> G_4 L_6
e( 17 - 17) = 6.17771 eV 1 --> ?
e( 18 - 18) = 6.17881 eV 1 --> ?
e( 19 - 20) = 6.71542 eV 2 --> G_4 L_6
e( 21 - 22) = 9.71686 eV 2 --> G_4 L_6
e( 23 - 24) = 9.89284 eV 2 --> G_4 L_6
e( 25 - 25) = 9.90802 eV 1 --> ?
e( 26 - 26) = 9.90828 eV 1 --> ?
e( 27 - 28) = 13.70106 eV 2 --> G_4 L_6
e( 29 - 29) = 15.96850 eV 1 --> ?
e( 30 - 31) = 15.97285 eV 2 --> G_4 L_6
e( 32 - 32) = 15.97848 eV 1 --> ?
e( 33 - 34) = 17.54594 eV 2 --> G_4 L_6
e( 35 - 36) = 17.82870 eV 2 --> G_4 L_6
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