[Pw_forum] Aluminium EPC at X
Amit Kumar
amit76.india at gmail.com
Sun Mar 25 19:58:12 CEST 2007
Respected Users,
I'm very much confused with the results of the electron-phonon coupling
of Aluminium
at X-point. You can see a large discrepancy in the results of Example
No. 7.
I hope developers have checked their results carefully before
keeping them on the web and
they must have some clarification of the above anomaly.
Someone can get some total value of lamda (say 0.38 for Al) by
manipulating some input parameters
in 100 ways.
However it does not imply al the ways are correct. Sometime some correct
results might be accidental.
So developers should check every part of the results carefully and
mention all the details in their
published paper instead of just giving an experimentally closed value
of lambda.
Check out the discrepancy even in the example given by developers.
::::::::::::::::
OLd version ::::
electron-phonon interaction ...
Gaussian Broadening: 0.010 Ry, ngauss= 1
DOS = 1.571147 states/spin/Ry/Unit Cell at Ef= 8.320258 eV
double delta at Ef = 11.225648
lambda( 1)= 0.159075 gamma= 8.614118 GHz
lambda( 2)= 0.159075 gamma= 8.614118 GHz
lambda( 3)= 0.003155 gamma= 0.507699 GHz
Gaussian Broadening: 0.020 Ry, ngauss= 1
DOS = 2.063779 states/spin/Ry/Unit Cell at Ef= 8.335249 eV
double delta at Ef = 18.003706
lambda( 1)= 0.227168 gamma= 16.158565 GHz
lambda( 2)= 0.227168 gamma= 16.158565 GHz
lambda( 3)= 0.186119 gamma= 39.344107 GHz
Gaussian Broadening: 0.030 Ry, ngauss= 1
DOS = 2.225322 states/spin/Ry/Unit Cell at Ef= 8.330057 eV
double delta at Ef = 16.640984
lambda( 1)= 0.192523 gamma= 14.766136 GHz
lambda( 2)= 0.192523 gamma= 14.766136 GHz
lambda( 3)= 0.205460 gamma= 46.832277 GHz
Gaussian Broadening: 0.040 Ry, ngauss= 1
DOS = 2.326737 states/spin/Ry/Unit Cell at Ef= 8.319465 eV
double delta at Ef = 14.664131
lambda( 1)= 0.176025 gamma= 14.116094 GHz
lambda( 2)= 0.176025 gamma= 14.116094 GHz
lambda( 3)= 0.151743 gamma= 36.164371 GHz
Gaussian Broadening: 0.050 Ry, ngauss= 1
DOS = 2.437502 states/spin/Ry/Unit Cell at Ef= 8.308700 eV
double delta at Ef = 13.504805
lambda( 1)= 0.157223 gamma= 13.208493 GHz
lambda( 2)= 0.157223 gamma= 13.208493 GHz
lambda( 3)= 0.127499 gamma= 31.832929 GHz
Gaussian Broadening: 0.060 Ry, ngauss= 1
DOS = 2.540670 states/spin/Ry/Unit Cell at Ef= 8.300510 eV
double delta at Ef = 12.914118
lambda( 1)= 0.139587 gamma= 12.223180 GHz
lambda( 2)= 0.139587 gamma= 12.223180 GHz
lambda( 3)= 0.123908 gamma= 32.245781 GHz
Gaussian Broadening: 0.070 Ry, ngauss= 1
DOS = 2.612585 states/spin/Ry/Unit Cell at Ef= 8.295170 eV
double delta at Ef = 12.624523
lambda( 1)= 0.127008 gamma= 11.436544 GHz
lambda( 2)= 0.127008 gamma= 11.436544 GHz
lambda( 3)= 0.124915 gamma= 33.427891 GHz
Gaussian Broadening: 0.080 Ry, ngauss= 1
DOS = 2.651928 states/spin/Ry/Unit Cell at Ef= 8.291972 eV
double delta at Ef = 12.510074
lambda( 1)= 0.119464 gamma= 10.919196 GHz
lambda( 2)= 0.119464 gamma= 10.919196 GHz
lambda( 3)= 0.127255 gamma= 34.566893 GHz
Gaussian Broadening: 0.090 Ry, ngauss= 1
DOS = 2.669093 states/spin/Ry/Unit Cell at Ef= 8.290116 eV
double delta at Ef = 12.474088
lambda( 1)= 0.115291 gamma= 10.605987 GHz
lambda( 2)= 0.115291 gamma= 10.605987 GHz
lambda( 3)= 0.130520 gamma= 35.683264 GHz
Gaussian Broadening: 0.100 Ry, ngauss= 1
DOS = 2.674519 states/spin/Ry/Unit Cell at Ef= 8.288962 eV
double delta at Ef = 12.456417
lambda( 1)= 0.112978 gamma= 10.414299 GHz
lambda( 2)= 0.112978 gamma= 10.414299 GHz
lambda( 3)= 0.134292 gamma= 36.789272 GHz
And check the
Newer Version :::::::::
. Diagonalizing the dynamical matrix
q = ( 0.000000000 0.000000000 1.000000000 )
**************************************************************************
omega( 1) = 6.150074 [THz] = 205.145746 [cm-1]
omega( 2) = 6.150074 [THz] = 205.145746 [cm-1]
omega( 3) = 9.705764 [THz] = 323.751591 [cm-1]
**************************************************************************
electron-phonon interaction ...
Gaussian Broadening: 0.010 Ry, ngauss= 0
DOS = 2.640036 states/spin/Ry/Unit Cell at Ef= 8.292189 eV
lambda( 1)= 0.1693 gamma= 16.15 GHz
lambda( 2)= 0.1696 gamma= 16.18 GHz
lambda( 3)= 0.1515 gamma= 35.98 GHz
Gaussian Broadening: 0.020 Ry, ngauss= 0
DOS = 2.665783 states/spin/Ry/Unit Cell at Ef= 8.295265 eV
lambda( 1)= 0.1342 gamma= 12.92 GHz
lambda( 2)= 0.1376 gamma= 13.25 GHz
lambda( 3)= 0.1441 gamma= 34.55 GHz
Gaussian Broadening: 0.030 Ry, ngauss= 0
DOS = 2.664312 states/spin/Ry/Unit Cell at Ef= 8.294084 eV
lambda( 1)= 0.1197 gamma= 11.51 GHz
lambda( 2)= 0.1231 gamma= 11.85 GHz
lambda( 3)= 0.1466 gamma= 35.14 GHz
Gaussian Broadening: 0.040 Ry, ngauss= 0
DOS = 2.668351 states/spin/Ry/Unit Cell at Ef= 8.290682 eV
lambda( 1)= 0.1148 gamma= 11.06 GHz
lambda( 2)= 0.1181 gamma= 11.39 GHz
lambda( 3)= 0.1470 gamma= 35.28 GHz
Gaussian Broadening: 0.050 Ry, ngauss= 0
DOS = 2.672172 states/spin/Ry/Unit Cell at Ef= 8.286936 eV
lambda( 1)= 0.1125 gamma= 10.85 GHz
lambda( 2)= 0.1156 gamma= 11.16 GHz
lambda( 3)= 0.1485 gamma= 35.71 GHz
Gaussian Broadening: 0.060 Ry, ngauss= 0
DOS = 2.674722 states/spin/Ry/Unit Cell at Ef= 8.283275 eV
lambda( 1)= 0.1107 gamma= 10.70 GHz
lambda( 2)= 0.1135 gamma= 10.96 GHz
lambda( 3)= 0.1508 gamma= 36.29 GHz
Gaussian Broadening: 0.070 Ry, ngauss= 0
DOS = 2.675808 states/spin/Ry/Unit Cell at Ef= 8.279572 eV
lambda( 1)= 0.1093 gamma= 10.57 GHz
lambda( 2)= 0.1116 gamma= 10.78 GHz
lambda( 3)= 0.1533 gamma= 36.91 GHz
Gaussian Broadening: 0.080 Ry, ngauss= 0
DOS = 2.675785 states/spin/Ry/Unit Cell at Ef= 8.275659 eV
lambda( 1)= 0.1082 gamma= 10.46 GHz
lambda( 2)= 0.1099 gamma= 10.63 GHz
lambda( 3)= 0.1558 gamma= 37.51 GHz
Gaussian Broadening: 0.090 Ry, ngauss= 0
DOS = 2.675260 states/spin/Ry/Unit Cell at Ef= 8.271439 eV
lambda( 1)= 0.1072 gamma= 10.36 GHz
lambda( 2)= 0.1086 gamma= 10.49 GHz
lambda( 3)= 0.1582 gamma= 38.07 GHz
Gaussian Broadening: 0.100 Ry, ngauss= 0
DOS = 2.674736 states/spin/Ry/Unit Cell at Ef= 8.266876 eV
lambda( 1)= 0.1063 gamma= 10.27 GHz
lambda( 2)= 0.1074 gamma= 10.37 GHz
lambda( 3)= 0.1603 gamma= 38.57 GHz
Number of q in the star = 3
List of q in the star:
1 0.000000000 0.000000000 1.000000000
2 1.000000000 0.000000000 0.000000000
3 0.000000000 1.000000000 0.000000000
One can easily notice that the above 2 results are not the same.
Moreover, the results are not well converged.
Please tell me
which value will you say the correct one????????
Gaussian Broadening: 0.090 Ry, ngauss= 0
DOS = 2.675260 states/spin/Ry/Unit Cell at Ef= 8.271439 eV
lambda( 3)= 0.1582 gamma= 38.07 GHz
Gaussian Broadening: 0.080 Ry, ngauss= 0
DOS = 2.675785 states/spin/Ry/Unit Cell at Ef= 8.275659 eV
lambda( 3)= 0.1558 gamma= 37.51 GHz
The value of lambda : 0.1470 or 0.1558 or 0.1582
are not the same.
By the way, manipulating the input parameters carefully one can
easily get the
total value of lambda very close to the experimental one in the both
version.
Looking forward to your kind explanation.
Regards,
Amit
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