Hi Pietro, Thank you for the reply.
This system actually has an issue with the symmetry while running an EPW calculation (which has been fixed temporarily for now in the code). I had the phonon done with splitting a job in each q-point generated by pw.x, and later when I ran an EPW, it crashed with error in the specific q-point which is not in the same order with ph.x. For many of the systems I checked, the way I run works. I am not really worried, but trying to understand what's going on with this specific case. Sincerely, Hari On Thu, Aug 6, 2020 at 12:06 PM Pietro Delugas <[email protected]> wrote: > Hi Hari > > > > They are generated by two different routines and probably with two > different algorithms. > > Why are you worried about their ordering ? > > > > they are two different things. > > > > One is a MP mesh used to estimate integrals of periodic functions in the > Brillouin Zone exploiting phase cancelations; they are used all together > to make an SCF calculation. > > The other one is a uniform grid of q points at each one of which to > compute independently a dynamical matrix using all k points (plus others) > of the previous list. Then taken all together the dynamical matrices > form the Fourier transform of the interatomic force constants in a 6X6X4 > supercell. > > > > Regards - Pietro > > > > > > > > > > Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for > Windows 10 > > > > *From: *Hari Paudyal <[email protected]> > *Sent: *Thursday, August 6, 2020 4:00 PM > *To: *Quantum Espresso users Forum <[email protected]> > *Subject: *[QE-users] difference in the order of k/q points with pw.x and > ph.x > > > > Hi all, > > > > I am doing a phonon calculation of a trigonal system with SG 164. I > noticed that the order of the k (q) points printed from pw.x and ph.x is > different for the same k (q) grids. > > > > my inputs/outputs are as the following: > > *pw.x input * *ph.x input* > > K_POINTS {automatic} ldisp = .true. > 6 6 4 0 0 0 nq1 = 6, nq2 = 6, > nq3 = 4 > > > > *pw.x output* > > number of k points= 24 Marzari-Vanderbilt smearing, width (Ry)= > 0.0200 > cart. coord. in units 2pi/alat > k( 1) = ( 0.0000000 0.0000000 0.0000000), wk = 0.0138889 > k( 2) = ( 0.0000000 0.0000000 0.1707981), wk = 0.0277778 > k( 3) = ( 0.0000000 0.0000000 -0.3415962), wk = 0.0138889 > k( 4) = ( 0.0000000 0.1924501 0.0000000), wk = 0.0833333 > k( 5) = ( 0.0000000 0.1924501 0.1707981), wk = 0.0833333 > k( 6) = ( 0.0000000 0.1924501 -0.3415962), wk = 0.0833333 > k( 7) = ( 0.0000000 0.3849002 0.0000000), wk = 0.0833333 > k( 8) = ( 0.0000000 0.3849002 0.1707981), wk = 0.0833333 > k( 9) = ( 0.0000000 0.3849002 -0.3415962), wk = 0.0833333 > k( 10) = ( 0.0000000 -0.5773503 0.0000000), wk = 0.0416667 > k( 11) = ( 0.0000000 -0.5773503 0.1707981), wk = 0.0833333 > k( 12) = ( 0.0000000 -0.5773503 -0.3415962), wk = 0.0416667 > k( 13) = ( 0.1666667 0.2886751 0.0000000), wk = 0.0833333 > k( 14) = ( 0.1666667 0.2886751 0.1707981), wk = 0.1666667 > k( 15) = ( 0.1666667 0.2886751 -0.3415962), wk = 0.0833333 > k( 16) = ( 0.1666667 0.4811252 0.0000000), wk = 0.1666667 > k( 17) = ( 0.1666667 0.4811252 0.1707981), wk = 0.1666667 > k( 18) = ( 0.1666667 0.4811252 -0.3415962), wk = 0.1666667 > k( 19) = ( 0.3333333 0.5773503 0.0000000), wk = 0.0277778 > k( 20) = ( 0.3333333 0.5773503 0.1707981), wk = 0.0555556 > k( 21) = ( 0.3333333 0.5773503 -0.3415962), wk = 0.0277778 > k( 22) = ( 0.0000000 0.1924501 -0.1707981), wk = 0.0833333 > k( 23) = ( 0.0000000 0.3849002 -0.1707981), wk = 0.0833333 > k( 24) = ( -0.1666667 0.4811252 -0.1707981), wk = 0.1666667 > > > > *ph.x output* > > Dynamical matrices for ( 6, 6, 4) uniform grid of q-points > ( 24 q-points): > N xq(1) xq(2) xq(3) > 1 0.000000000 0.000000000 0.000000000 > 2 0.000000000 0.000000000 0.170798095 > 3 0.000000000 0.000000000 -0.341596190 > 4 0.000000000 0.192450090 0.000000000 > 5 0.000000000 0.192450090 0.170798095 > 6 0.000000000 0.192450090 -0.341596190 > 7 0.000000000 0.192450090 -0.170798095 > 8 0.000000000 0.384900179 0.000000000 > 9 0.000000000 0.384900179 0.170798095 > 10 0.000000000 0.384900179 -0.341596190 > 11 0.000000000 0.384900179 -0.170798095 > 12 0.000000000 -0.577350269 0.000000000 > 13 0.000000000 -0.577350269 0.170798095 > 14 0.000000000 -0.577350269 -0.341596190 > 15 0.166666667 0.288675135 0.000000000 > 16 0.166666667 0.288675135 0.170798095 > 17 0.166666667 0.288675135 -0.341596190 > 18 0.166666667 0.481125224 0.000000000 > 19 0.166666667 0.481125224 0.170798095 > 20 0.166666667 0.481125224 -0.341596190 > 21 0.166666667 0.481125224 -0.170798095 > 22 0.333333333 0.577350269 0.000000000 > 23 0.333333333 0.577350269 0.170798095 > 24 0.333333333 0.577350269 -0.341596190 > > > > For example, you can see the 7th point from pw.x is the 8th point from > ph.x and so on. > > > > Any suggestions and explanations are highly appreciated. > > > > Sincerely, > > Hari Paudyal > > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
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