<br><br>
Respected Users,<br>
<br>
I'm very much confused with the Electron-phonon output of Example 7.<br>
Please check it out:<br>
<br>
1 . KPOINT 16 16 16 for scf.fit and 2 2 2 for scf calculation.<br>
<br>
Gaussian Broadening: 0.090 Ry, ngauss= 0<br>
DOS = 2.674745 states/spin/Ry/Unit Cell at Ef= 8.266810 eV <br>
lambda( 1)= 0.1373 gamma= 15.97 GHz<br>
lambda( 2)= 0.1116 gamma= 12.97 GHz<br>
lambda( 3)= 0.0504 gamma= 6.93 GHz<br>
<br>
<br>
Gaussian Broadening: 0.10 Ry, ngauss= 0<br>
DOS = 2.674314 states/spin/Ry/Unit Cell at Ef= 8.266772 eV<br>
lambda( 1)= 0.1403 gamma= 16.32 GHz<br>
lambda( 2)= 0.1132 gamma= 13.16 GHz<br>
lambda( 3)= 0.0520 gamma= 7.15 GHz<br>
<br>
<br>
<br>
2. KPOINT 16 16 16 for scf.fit and 8 8 8 for scf calculation.<br>
<br>
Gaussian Broadening: 0.090 Ry, ngauss= 0<br>
DOS = 2.673746 states/spin/Ry/Unit Cell at Ef= 8.271433 eV<br>
lambda( 1)= 0.0828 gamma= 8.96 GHz<br>
lambda( 2)= 0.1720 gamma= 26.90 GHz<br>
lambda( 3)= 0.1742 gamma= 27.24 GHz<br>
<br>
<br>
Gaussian Broadening: 0.10 Ry, ngauss= 0<br>
DOS = 2.674314 states/spin/Ry/Unit Cell at Ef= 8.266772 eV<br>
lambda( 1)= 0.0831 gamma= 8.99 GHz<br>
lambda( 2)= 0.1721 gamma= 26.93 GHz<br>
lambda( 3)= 0.1740 gamma= 27.22 GHz<br>
<br>
So I thought great I got convergency so easily.<br>
lambda( 2)= 0.1720 gamma= 26.90 GHz<br>
lambda( 3)= 0.1742 gamma= 27.24 GHz <br>
<br>
and <br>
<br>
lambda( 2)= 0.1721 gamma= 26.93 GHz<br>
lambda( 3)= 0.1740 gamma= 27.22 GHz<br>
<br>
Very excellent results.<br>
<br>
But. life is not so simple. Bad luck.<br>
With even more K points again results start to become worse instead of being better.<br>
<br>
Please check it out :<br>
<br>
<br>
3. KPOINT 32 32 32 for
scf.fit and 16 16 16 for scf
calculation.<br>
<br>
Gaussian Broadening: 0.090 Ry, ngauss= 0<br>
DOS = 2.675256 states/spin/Ry/Unit Cell at Ef= 8.271367 eV<br>
lambda( 1)= 0.0799 gamma= 9.12 GHz <br>
lambda( 2)= 0.1703 gamma= 28.62 GHz<br>
lambda( 3)= 0.1705 gamma= 28.64 GHz<br>
<br>
Gaussian Broadening: 0.10 Ry, ngauss= 0<br>
DOS = 2.674732 states/spin/Ry/Unit Cell at Ef= 8.266803 eV<br>
lambda( 1)= 0.0799 gamma= 9.12 GHz<br>
lambda( 2)= 0.1686 gamma= 28.32 GHz<br>
lambda( 3)= 0.1687 gamma= 28.34 GHz<br>
<br>
<br>
4. KPOINT 64 64 64 for
scf.fit and 32 32 32 for scf
calculation.<br>
<br>
<br>
Gaussian Broadening: 0.090 Ry, ngauss= 0<br>
DOS = 2.675273 states/spin/Ry/Unit Cell at Ef= 8.271375 eV<br>
lambda( 1)= 0.0801 gamma= 9.07 GHz<br>
lambda( 2)= 0.1726 gamma= 28.29 GHz<br>
lambda( 3)= 0.1726 gamma= 28.29 GHz<br>
<br>
<br>
Gaussian Broadening: 0.10 Ry, ngauss= 0<br>
DOS = 2.674745 states/spin/Ry/Unit Cell at Ef= 8.266810 eV<br>
lambda( 1)= 0.0802 gamma= 9.08 GHz<br>
lambda( 2)= 0.1708 gamma= 27.99 GHz<br>
lambda( 3)= 0.1708 gamma= 27.99 GHz<br>
<br>
<br>
Would anybody tell me the
reason, Why the case (2) ( for magic number <br>
KPOINT 16 16 16
for scf.fit and 8 8 8 for scf
calculation) is so kind <br>
to us?????? How far we will go to get the converged value???<br>
Where can we stop????<br>
It's really confusing.<br>
<br>
Looking forward to your help.<br>
<br>
Regards,<br>
Amit<br>
<br>