<div dir="ltr">Hi,<div><br></div><div>I think, you are on the correct way, but you are taking double points on every k-points (if you add all it is 128 but it should be 4x4x4 = 64). So, take half on each. This can be understood by considering the Gamma (0.0 0.0 0.0) point only, there should be only one Gamma point, no?</div><div><br></div><div>Best,</div><div>Hari Paudyal<br>SUNY Binghamton University</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Mar 14, 2019 at 2:14 PM Arena Konta <<a href="mailto:qe6user@gmail.com">qe6user@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Dear Professors Paolo and and Hari,<br>
<br>
I appreciate your both help. However, I am still a little bit confused which weights should I chose for lambda.x file. For example:<br>
<br>
bravais-lattice index = 7<br>
lattice parameter (alat) = 7.9506 a.u.<br>
unit-cell volume = 591.7416 (a.u.)^3<br>
<br>
celldm(1)= 7.950626 celldm(2)= 0.000000 celldm(3)= 2.354822<br>
celldm(4)= 0.000000 celldm(5)= 0.000000 celldm(6)= 0.000000<br>
<br>
scf calculations on the mesh 4x4x4 give me:<br>
<br>
number of k points= 13 Marzari-Vanderbilt smearing, width (Ry)= 0.0200<br>
cart. coord. in units 2pi/alat<br>
k( 1) = ( 0.0000000 0.0000000 0.0000000), wk = 0.0312500 = 2<br>
k( 2) = ( -0.2500000 0.0000000 0.1061651), wk = 0.2500000 = 16<br>
k( 3) = ( 0.5000000 0.0000000 -0.2123303), wk = 0.1250000 = 8<br>
k( 4) = ( -0.2500000 0.2500000 0.2123303), wk = 0.2500000 = 16<br>
k( 5) = ( 0.5000000 0.2500000 -0.1061651), wk = 0.5000000 = 32<br>
k( 6) = ( 0.2500000 0.2500000 0.0000000), wk = 0.1250000 = 8<br>
k( 7) = ( 0.5000000 -0.5000000 -0.4246605), wk = 0.0625000 = 4<br>
k( 8) = ( 0.0000000 0.0000000 0.2123303), wk = 0.0625000 = 4<br>
k( 9) = ( 0.7500000 0.0000000 -0.1061651), wk = 0.2500000 = 16<br>
k( 10) = ( 0.5000000 0.0000000 0.0000000), wk = 0.1250000 = 8<br>
k( 11) = ( 0.7500000 -0.7500000 -0.4246605), wk = 0.1250000 = 8<br>
k( 12) = ( 0.5000000 -0.5000000 -0.2123303), wk = 0.0625000 = 4<br>
k( 13) = ( 0.0000000 0.0000000 -0.4246605), wk = 0.0312500 = 2<br>
(there is no inversion in crystal structure)<br>
<br>
ph.x calculations are following: <br>
<br>
Dynamical matrices for ( 4, 4, 4) uniform grid of q-points<br>
( 13q-points):<br>
N xq(1) xq(2) xq(3)<br>
1 0.000000000 0.000000000 0.000000000<br>
2 -0.250000000 0.000000000 0.106165127<br>
3 0.500000000 -0.000000000 -0.212330253<br>
4 -0.250000000 0.250000000 0.212330253<br>
5 0.500000000 0.250000000 -0.106165127<br>
6 0.250000000 0.250000000 0.000000000<br>
7 0.500000000 -0.500000000 -0.424660507<br>
8 0.000000000 0.000000000 0.212330253<br>
9 0.750000000 -0.000000000 -0.106165127<br>
10 0.500000000 -0.000000000 0.000000000<br>
11 0.750000000 -0.750000000 -0.424660507<br>
12 0.500000000 -0.500000000 -0.212330253<br>
13 0.000000000 -0.000000000 -0.424660507<br>
<br>
Therefore, we can say that both q- and k-meshes are "exactly" the same in scf and ph calculations. However, when I generate k-mesh using kpoints.x, the set is equivalent, but the weights and order are different:<br>
<br>
<br>
<br>
***************************************************<br>
* *<br>
* Welcome to the special points world! *<br>
*________________________________________________ *<br>
* 1 = cubic p (sc ) 8 = orthor p (so ) *<br>
* 2 = cubic f (fcc) 9 = orthor base-cent. *<br>
* 3 = cubic i (bcc) 10 = orthor face-cent. *<br>
* 4 = hex & trig p 11 = orthor body-cent. *<br>
* 5 = trigonal r 12 = monoclinic p *<br>
* 6 = tetrag p (st ) 13 = monocl base-cent. *<br>
* 7 = tetrag i (bct) 14 = triclinic p *<br>
***************************************************<br>
<br>
bravais lattice >> 7<br>
filout [mesh_k] >> TEST<br>
enter celldm(3) >> 2.35482<br>
mesh: n1 n2 n3 >> 4 4 4<br>
mesh: k1 k2 k3 (0 no shift, 1 shifted) >> 0 0 0<br>
write all k? [f] >><br>
<br>
# of k-points == 13 of 64<br>
<br>
<br>
13<br>
1 0.0000000 0.0000000 0.0000000 1.00<br>
2 0.2500000 -0.2500000 0.0000000 4.00<br>
3 0.5000000 -0.5000000 0.0000000 2.00<br>
4 0.0000000 0.2500000 0.1061652 8.00<br>
5 0.5000000 -0.2500000 0.1061652 16.00<br>
6 0.0000000 0.5000000 0.2123305 4.00<br>
7 0.2500000 0.2500000 0.2123305 8.00<br>
8 0.0000000 0.0000000 0.2123305 2.00<br>
9 0.5000000 -0.5000000 0.2123305 2.00<br>
10 0.0000000 0.2500000 0.3184957 8.00<br>
11 0.0000000 0.5000000 0.4246609 4.00<br>
12 0.2500000 0.2500000 0.4246609 4.00<br>
13 0.0000000 0.0000000 0.4246609 1.00<br>
<br>
Which weights should I use in my el-ph calculations?<br>
<br>
<br>
-- <br>
with regards<br>
<br>
Arena Konta<br>
The Institute of Thermophysics in Novosibirsk Scientific Center<br>
<br>
<br>
<br>
<br>
<br>
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