[Pw_forum] Generating K points for Wurzite Structure using crystal_b

lateef mustapha muslaty2k at yahoo.com
Fri Apr 1 15:51:58 CEST 2016


Dear Apsi and Mkondrin

Thank You for your wonderful responses, Below are my responses to your question/comment/observations


@ Mkondrin

 (It seems to me that you have calculated dispersion of not cubic boron  nitride (which has wurtzite structure) but rather that of hexagonal BN)

Yes, I am calculating the dispersion for wurzite structure. Is there any problem with my input file as regard that ?


@Apsi 

 I also do not understand why you no longer have the exact hexagonal symmetry laterally;  Am interested in the wurzite bulk properrties 

further, ecutrho => 4 * ecutwfc - That should be the default value from my input file. Do you suggest that I write it?

, otherwise you might get some nasty effects (your input does not reveal which pseudo potentials/PAW data sets you were employing); Yes, the dispersion was truly nasty. Any help!

why using the cold smearing if the system would probably be semi-conducting or even insulating; Could you suggest the best for semiconductor ? with references

and the kpoint with high symmetry would actually be (1/3,1/3,0), not (0.3,0.3,0): any reference as regard this. 

Thanks


--------------------------------------------
On Fri, 4/1/16, pw_forum-request at pwscf.org <pw_forum-request at pwscf.org> wrote:

 Subject: Pw_forum Digest, Vol 105, Issue 1
 To: pw_forum at pwscf.org
 Date: Friday, April 1, 2016, 6:00 AM
 
 Send Pw_forum mailing list
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 Today's Topics:
 
    1. Generating K points for Wurzite
 Structure using crystal_b
       (lateef mustapha)
    2. Re: Generating K points for Wurzite
 Structure using    crystal_b
       (mkondrin)
    3. VC_relax (Vishal Gupta)
    4. Re: Generating K points for Wurzite
 Structure using crystal_b
       (Ari P Seitsonen)
    5. Re: VC_relax (Ari P Seitsonen)
    6. Allocation would exceed memory limit
       (Mofrad, Amir Mehdi (MU-Student))
    7. Re: VC_relax (Vishal Gupta)
    8. Re: VC_relax (Vincenzo Verdolino)
    9. Computer do not respond when running
 pwcond (Yangchuan Li)
 
 
 ----------------------------------------------------------------------
 
 Message: 1
 Date: Thu, 31 Mar 2016 11:04:39 +0000 (UTC)
 From: lateef mustapha <muslaty2k at yahoo.com>
 Subject: [Pw_forum] Generating K points for Wurzite
 Structure using
     crystal_b
 To: <pw_forum at pwscf.org>
 Message-ID:
     <342127751.209575.1459422279109.JavaMail.yahoo at mail.yahoo.com>
 Content-Type: text/plain; charset=UTF-8
 
 Dear QE Users, I just successfully generated the k points
 for plotting the band structure of a wurzite structure. The
 crystal direction of the calculated are approximated and I
 guess that was the reason why my band dispersion were fairly
 distorted. Any advice ?
 see Input file below
 
 Reading   16 bands at 
    91 k-points
 Range:   -9.1640   28.7880eV 
 Emin, Emax > -9.164 28.788
 high-symmetry point:  0.0000 0.0000
 0.0000   x
 coordinate   0.0000
 high-symmetry point:  0.0000 0.0000
 0.3019   x
 coordinate   0.3019
 high-symmetry point:  0.4993 0.2883
 0.3019   x
 coordinate   0.8784
 high-symmetry point:  0.4993 0.2883
 0.0000   x
 coordinate   1.1803
 high-symmetry point:  0.0000 0.0000
 0.0000   x
 coordinate   1.7569
 high-symmetry point:  0.2996 0.5189
 0.0000   x
 coordinate   2.3561
 high-symmetry point:  0.2996 0.5189
 0.3019   x
 coordinate   2.6580
 
 &CONTROL
     restart_mode = 'from_scratch' 
     tstress = .TRUE.,
     tprnfor = .TRUE. , 
     calculation = 'bands' 
     pseudo_dir  =
 '/home/musty/esp/pseudo/PW91'
     prefix = 'BN'
  /
  &SYSTEM
     ibrav =  4, 
     celldm(1) = 4.82,
     celldm(3) = 1.65,
     occupations='smearing' ,
     smearing='mp',
     nat =  4,  
     ntyp = 2,
     nbnd = 16,
     degauss=0.06,
     ecutwfc = 65,
     ecutrho = 200,
  /
  &ELECTRONS
     diagonalization='david'
     mixing_mode = 'plain'
     mixing_beta = 0.7
     conv_thr =  1.0d-8
  /
 ATOMIC_SPECIES
  B  10.811 
  N  14.001  
 
 CELL_PARAMETERS (alat=  4.82000000)
    1.001361289   0.000000000   0.000000000
  
 -0.500680645   0.867204315   0.000000000
    0.000000000   0.000000000   1.656271159
 
 ATOMIC_POSITIONS (crystal)
 B       
 0.000000000   0.000000000   0.000317468
 B       
 0.666666700   0.333333300   0.500317468
 N       
 0.000000000   0.000000000   0.374682532
 N       
 0.666666700   0.333333300   0.874682532   
 
 K_POINTS crystal_b
 7
 0.0 0.0 0.0 10
 0.0 0.0 0.5 20
 0.5 0.0 0.5 10
 0.5 0.0 0.0 20
 0.0 0.0 0.0 20
 0.3 0.3 0.0 10
 0.3 0.3 0.5 1
 
 Mustapha L.O
 Graduate Student, University of Ibadan. Nigeria
 
 
 ------------------------------
 
 Message: 2
 Date: Thu, 31 Mar 2016 17:01:05 +0400
 From: mkondrin <mkondrin at hppi.troitsk.ru>
 Subject: Re: [Pw_forum] Generating K points for Wurzite
 Structure
     using    crystal_b
 To: lateef mustapha <muslaty2k at yahoo.com>,
 PWSCF Forum
     <pw_forum at pwscf.org>
 Message-ID: <56FD1F91.8000806 at hppi.troitsk.ru>
 Content-Type: text/plain; charset=ISO-8859-1; format=flowed
 
 On 31.03.2016 15:04, lateef mustapha wrote:
 > Dear QE Users, I just successfully generated the k
 points for plotting the band structure of a wurzite
 structure. The crystal direction of the calculated are
 approximated and I guess that was the reason why my band
 dispersion were fairly distorted. Any advice ?
 Dear Lateef Mustapha!
 
 It seems to me that you have calculated dispersion of not
 cubic boron 
 nitride (which has wurtzite structure) but rather that of
 hexagonal BN
 
 M. V. Kondrin
 High Pressure Physics Institute  RAS
 
 
 > see Input file below
 >
 > Reading   16 bands at 
    91 k-points
 >
 Range:   -9.1640   28.7880eV 
 Emin, Emax > -9.164 28.788
 > high-symmetry point:  0.0000 0.0000
 0.0000   x
 coordinate   0.0000
 > high-symmetry point:  0.0000 0.0000
 0.3019   x
 coordinate   0.3019
 > high-symmetry point:  0.4993 0.2883
 0.3019   x
 coordinate   0.8784
 > high-symmetry point:  0.4993 0.2883
 0.0000   x
 coordinate   1.1803
 > high-symmetry point:  0.0000 0.0000
 0.0000   x
 coordinate   1.7569
 > high-symmetry point:  0.2996 0.5189
 0.0000   x
 coordinate   2.3561
 > high-symmetry point:  0.2996 0.5189
 0.3019   x
 coordinate   2.6580
 >
 > &CONTROL
 >      restart_mode = 'from_scratch'
 >      tstress = .TRUE.,
 >      tprnfor = .TRUE. ,
 >      calculation = 'bands'
 >      pseudo_dir  =
 '/home/musty/esp/pseudo/PW91'
 >      prefix = 'BN'
 >   /
 >   &SYSTEM
 >      ibrav =  4,
 >      celldm(1) = 4.82,
 >      celldm(3) = 1.65,
 >      occupations='smearing' ,
 >      smearing='mp',
 >      nat =  4,
 >      ntyp = 2,
 >      nbnd = 16,
 >      degauss=0.06,
 >      ecutwfc = 65,
 >      ecutrho = 200,
 >   /
 >   &ELECTRONS
 >      diagonalization='david'
 >      mixing_mode = 'plain'
 >      mixing_beta = 0.7
 >      conv_thr =  1.0d-8
 >   /
 > ATOMIC_SPECIES
 >   B  10.811
 >   N  14.001
 >
 > CELL_PARAMETERS (alat=  4.82000000)
 > 
    1.001361289   0.000000000   0.000000000
 >   
 -0.500680645   0.867204315   0.000000000
 > 
    0.000000000   0.000000000   1.656271159
 >
 > ATOMIC_POSITIONS (crystal)
 > B       
 0.000000000   0.000000000   0.000317468
 > B       
 0.666666700   0.333333300   0.500317468
 > N       
 0.000000000   0.000000000   0.374682532
 > N       
 0.666666700   0.333333300   0.874682532
 >
 > K_POINTS crystal_b
 > 7
 > 0.0 0.0 0.0 10
 > 0.0 0.0 0.5 20
 > 0.5 0.0 0.5 10
 > 0.5 0.0 0.0 20
 > 0.0 0.0 0.0 20
 > 0.3 0.3 0.0 10
 > 0.3 0.3 0.5 1
 >
 > Mustapha L.O
 > Graduate Student, University of Ibadan. Nigeria
 > _______________________________________________
 > Pw_forum mailing list
 > Pw_forum at pwscf.org
 > http://pwscf.org/mailman/listinfo/pw_forum
 >
 
 
 
 ------------------------------
 
 Message: 3
 Date: Thu, 31 Mar 2016 20:06:39 +0530
 From: Vishal Gupta <vishal.gupta at iitrpr.ac.in>
 Subject: [Pw_forum] VC_relax
 To: PWSCF Forum <pw_forum at pwscf.org>
 Message-ID:
     <CANAZiL95TQ-kt6roCdmNTOPLJ2RspU0+zYpGh7RyenBsgw9P3Q at mail.gmail.com>
 Content-Type: text/plain; charset="utf-8"
 
 Hi all,
 I've been running a vc_relax calculation on a 40 atom
 system. The
 calculation works fine for some cycles. The total force had
 come down to
 0.108. After some time. the force started increasing and now
 the iterations
 don't converge even in 400 steps. The input file is
  /
  &SYSTEM
                
        ibrav = 0,
                
          nat = 40,
                
         ntyp = 1,
                
      ecutwfc = 12 ,
  /
  &ELECTRONS
              
    mixing_beta = 0.3 ,
          
    diagonalization = 'david' ,
          
    electron_maxstep = 200 ,
  /
 
 [&Ions/]
 /
 &CELL
 cell_dynamics= 'sd' ,
 cell_dofree='xy' ,
 /
 
 CELL_PARAMETERS angstrom
     22.265358047804796   
 0.000000000000000    0.000000000000000
  
    0.000000000000000   11.131216979724510 
   0.000000000000000
      0.000000000000000   
 0.000000000000000   10.000000000000000
 
 P.S. Ive tried changing cell dynamics to 'damp-pr' , 'sd'
 and 'damp-w', but
 the same problem persists.
 Can anybody Please help me identifying the mistake ?
 Thank You.
 Best Regards,
 Vishal Gupta
 
 B.Tech. 3rd year Mechanical
 Indian Institute of Technology Ropar
 Rupnagar (140001), Punjab, India.
 Email :- vishal.gupta at iitrpr.ac.in
 RMML, IIT Ropar
 <https://sites.google.com/a/iitrpr.ac.in/ropar-mechanics-of-materials-laboratory/people>
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 ------------------------------
 
 Message: 4
 Date: Thu, 31 Mar 2016 17:38:37 +0200 (CEST)
 From: Ari P Seitsonen <Ari.P.Seitsonen at iki.fi>
 Subject: Re: [Pw_forum] Generating K points for Wurzite
 Structure
     using crystal_b
 To: PWSCF Forum <pw_forum at pwscf.org>
 Message-ID: <alpine.DEB.2.10.1603311734090.23473 at wigner.ens.fr>
 Content-Type: text/plain; charset="iso-8859-15"
 
 
 Dear Mustapha,
 
    Adding to the comment of M V Kondrin, some
 comments: I also do not 
 understand why you no longer have the exact hexagonal
 symmetry laterally; 
 further, ecutrho => 4 * ecutwfc, otherwise you might get
 some nasty 
 effects (your input does not reveal which pseudo
 potentials/PAW data sets 
 you were employing); why using the cold smearing if the
 system would 
 probably be semi-conducting or even insulating; and the k
 point with high 
 symmetry would actually be (1/3,1/3,0), not (0.3,0.3,0).
 
      Greetings from Paris,
 
         apsi
 
 -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
    Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi
 / http://www.iki.fi/~apsi/
      Ecole Normale Sup?rieure (ENS),
 D?partement de Chimie, Paris
      Mobile (F) : +33 789 37 24 25 
   (CH) : +41 79 71 90 935
 
 
 On Thu, 31 Mar 2016, lateef mustapha wrote:
 
 > Dear QE Users, I just successfully generated the k
 points for plotting the band structure of a wurzite
 structure. The crystal direction of the calculated are
 approximated and I guess that was the reason why my band
 dispersion were fairly distorted. Any advice ?
 > see Input file below
 >
 > Reading   16 bands at 
    91 k-points
 >
 Range:   -9.1640   28.7880eV 
 Emin, Emax > -9.164 28.788
 > high-symmetry point:  0.0000 0.0000
 0.0000   x
 coordinate   0.0000
 > high-symmetry point:  0.0000 0.0000
 0.3019   x
 coordinate   0.3019
 > high-symmetry point:  0.4993 0.2883
 0.3019   x
 coordinate   0.8784
 > high-symmetry point:  0.4993 0.2883
 0.0000   x
 coordinate   1.1803
 > high-symmetry point:  0.0000 0.0000
 0.0000   x
 coordinate   1.7569
 > high-symmetry point:  0.2996 0.5189
 0.0000   x
 coordinate   2.3561
 > high-symmetry point:  0.2996 0.5189
 0.3019   x
 coordinate   2.6580
 >
 > &CONTROL
 >    restart_mode = 'from_scratch'
 >    tstress = .TRUE.,
 >    tprnfor = .TRUE. ,
 >    calculation = 'bands'
 >    pseudo_dir  =
 '/home/musty/esp/pseudo/PW91'
 >    prefix = 'BN'
 > /
 > &SYSTEM
 >    ibrav =  4,
 >    celldm(1) = 4.82,
 >    celldm(3) = 1.65,
 >    occupations='smearing' ,
 >    smearing='mp',
 >    nat =  4,
 >    ntyp = 2,
 >    nbnd = 16,
 >    degauss=0.06,
 >    ecutwfc = 65,
 >    ecutrho = 200,
 > /
 > &ELECTRONS
 >    diagonalization='david'
 >    mixing_mode = 'plain'
 >    mixing_beta = 0.7
 >    conv_thr =  1.0d-8
 > /
 > ATOMIC_SPECIES
 > B  10.811
 > N  14.001
 >
 > CELL_PARAMETERS (alat=  4.82000000)
 >   1.001361289   0.000000000   0.000000000
 > 
 -0.500680645   0.867204315   0.000000000
 >   0.000000000   0.000000000   1.656271159
 >
 > ATOMIC_POSITIONS (crystal)
 > B       
 0.000000000   0.000000000   0.000317468
 > B       
 0.666666700   0.333333300   0.500317468
 > N       
 0.000000000   0.000000000   0.374682532
 > N       
 0.666666700   0.333333300   0.874682532
 >
 > K_POINTS crystal_b
 > 7
 > 0.0 0.0 0.0 10
 > 0.0 0.0 0.5 20
 > 0.5 0.0 0.5 10
 > 0.5 0.0 0.0 20
 > 0.0 0.0 0.0 20
 > 0.3 0.3 0.0 10
 > 0.3 0.3 0.5 1
 >
 > Mustapha L.O
 > Graduate Student, University of Ibadan. Nigeria
 > _______________________________________________
 > Pw_forum mailing list
 > Pw_forum at pwscf.org
 > http://pwscf.org/mailman/listinfo/pw_forum
 >
 
 ------------------------------
 
 Message: 5
 Date: Thu, 31 Mar 2016 17:47:51 +0200 (CEST)
 From: Ari P Seitsonen <Ari.P.Seitsonen at iki.fi>
 Subject: Re: [Pw_forum] VC_relax
 To: PWSCF Forum <pw_forum at pwscf.org>
 Message-ID: <alpine.DEB.2.10.1603311745320.23473 at wigner.ens.fr>
 Content-Type: text/plain; charset="utf-8"
 
 
 Dear Vishal Gupta,
 
    Your cut-off energy looks _very_ low, no
 matter which elements/pseudo 
 potentials you do employ. Probably your system becomes
 metallic upon the 
 relaxation, so I would include some kind of broadening of
 the occupation 
 numbers, in addition possibly using the mixing mode
 'local-TF', if you 
 have vacuum in your system.
 
      Greetings,
 
         apsi
 
 -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
    Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi
 / http://www.iki.fi/~apsi/
      Ecole Normale Sup?rieure (ENS),
 D?partement de Chimie, Paris
      Mobile (F) : +33 789 37 24 25 
   (CH) : +41 79 71 90 935
 
 
 On Thu, 31 Mar 2016, Vishal Gupta wrote:
 
 > Hi all,I've been running a vc_relax calculation on a 40
 atom system. The calculation works fine for some
 > cycles. The total force had come down to 0.108. After
 some time.?the force started increasing and now the
 > iterations don't converge even in 400 steps. The input
 file is
 > ?/
 > ?&SYSTEM
 > ? ? ? ? ? ? ? ? ? ? ? ?ibrav = 0,
 > ? ? ? ? ? ? ? ? ? ? ? ? ?nat = 40,
 > ? ? ? ? ? ? ? ? ? ? ? ? ntyp = 1,
 > ? ? ? ? ? ? ? ? ? ? ?ecutwfc = 12 ,
 > ?/
 > ?&ELECTRONS
 > ? ? ? ? ? ? ? ? ?mixing_beta = 0.3 ,
 > ? ? ? ? ? ? ?diagonalization = 'david' ,
 > ? ? ? ? ? ? ?electron_maxstep = 200 ,
 > ?/
 > 
 > [&Ions/]
 > /
 > &CELL
 > cell_dynamics= 'sd' ,
 > cell_dofree='xy' ,
 > /
 > 
 > CELL_PARAMETERS angstrom
 > ? ? 22.265358047804796 ? ?0.000000000000000 ?
 ?0.000000000000000
 > ? ? ?0.000000000000000 ? 11.131216979724510 ?
 ?0.000000000000000
 > ? ? ?0.000000000000000 ? ?0.000000000000000 ?
 10.000000000000000
 > 
 > P.S. Ive tried changing cell dynamics to 'damp-pr' ,
 'sd' and 'damp-w', but the same problem persists.
 > Can anybody Please help me identifying the mistake ?
 > Thank You.
 > Best Regards,
 > Vishal Gupta
 > 
 > B.Tech. 3rd year Mechanical
 > 
 > Indian Institute of Technology Ropar
 > Rupnagar (140001), Punjab, India.
 > Email :-?vishal.gupta at iitrpr.ac.in
 > RMML, IIT Ropar
 > 
 > 
 > 
 > [487a748cedfb942f92401d52262f336d11784524388949.png]
 > 
 >
 
 ------------------------------
 
 Message: 6
 Date: Thu, 31 Mar 2016 16:25:12 +0000
 From: "Mofrad, Amir Mehdi (MU-Student)" <amzf5 at mail.missouri.edu>
 Subject: [Pw_forum] Allocation would exceed memory limit
 To: PWSCF Forum <pw_forum at pwscf.org>
 Message-ID:
     <BLUPR01MB134520A4615885AFCAF73F8CA7990 at BLUPR01MB1345.prod.exchangelabs.com>
     
 Content-Type: text/plain; charset="iso-8859-1"
 
 Dear all QE users and developers,
 
 
 I am trying to do a vc-relax simulation on a certain type of
 zeolite (EMT). However, I keep getting the following error
 at the end of my output file (where the simulation has
 stopped/killed):
 
 Operating system error: Cannot allocate memory
 Allocation would exceed memory limit
 
 
 The problem is that I have been doing the same simulation on
 other types of zeolites (which have lower numbers of atoms
 per unit cell) and never got that error. Attached you will
 find my input file in case you might take a look at.
 
 
 Any help would be thoroughly appreciated.
 
 
 Best,
 
 
 Amir M. Mofrad
 
 University of Missouri
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 ------------------------------
 
 Message: 7
 Date: Thu, 31 Mar 2016 23:06:22 +0530
 From: Vishal Gupta <vishal.gupta at iitrpr.ac.in>
 Subject: Re: [Pw_forum] VC_relax
 To: Ari Paavo Seitsonen <Ari.P.Seitsonen at iki.fi>,   
 PWSCF Forum
     <pw_forum at pwscf.org>
 Message-ID:
    
 <CANAZiL8cc+xLq0KQPKiqLUt02vosb8DtO8cjEWyh2Qf==3iC7w at mail.gmail.com>
 Content-Type: text/plain; charset="utf-8"
 
 Dear Ari Paavo,
 Thank you for your informative reply. Can you please tell me
 how to broaden
 the occupation numbers ?
 Sorry,  I am a little new at this.
 Thank you.
 Best Regards,
 Vishal
 
 On Thu, Mar 31, 2016 at 9:17 PM, Ari P Seitsonen <Ari.P.Seitsonen at iki.fi>
 wrote:
 
 >
 > Dear Vishal Gupta,
 >
 >   Your cut-off energy looks _very_ low,
 no matter which elements/pseudo
 > potentials you do employ. Probably your system becomes
 metallic upon the
 > relaxation, so I would include some kind of broadening
 of the occupation
 > numbers, in addition possibly using the mixing mode
 'local-TF', if you have
 > vacuum in your system.
 >
 >     Greetings,
 >
 >        apsi
 >
 >
 >
 -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
 >   Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi
 / http://www.iki.fi/~apsi/
 >     Ecole Normale Sup?rieure (ENS),
 D?partement de Chimie, Paris
 >     Mobile (F) : +33 789 37 24
 25    (CH) : +41 79 71 90 935
 >
 >
 > On Thu, 31 Mar 2016, Vishal Gupta wrote:
 >
 > Hi all,I've been running a vc_relax calculation on a 40
 atom system. The
 >> calculation works fine for some
 >>
 >> cycles. The total force had come down to 0.108.
 After some time. the
 >> force started increasing and now the
 >> iterations don't converge even in 400 steps. The
 input file is
 >>  /
 >>  &SYSTEM
 >>             
           ibrav = 0,
 >>             
             nat = 40,
 >>             
            ntyp = 1,
 >>             
         ecutwfc = 12 ,
 >>  /
 >>  &ELECTRONS
 >>             
     mixing_beta = 0.3 ,
 >>             
 diagonalization = 'david' ,
 >>             
 electron_maxstep = 200 ,
 >>  /
 >>
 >> [&Ions/]
 >> /
 >> &CELL
 >> cell_dynamics= 'sd' ,
 >> cell_dofree='xy' ,
 >> /
 >>
 >> CELL_PARAMETERS angstrom
 >>     22.265358047804796 
   0.000000000000000    0.000000000000000
 >>     
 0.000000000000000   11.131216979724510 
   0.000000000000000
 >>      0.000000000000000   
 0.000000000000000   10.000000000000000
 >>
 >> P.S. Ive tried changing cell dynamics to 'damp-pr'
 , 'sd' and 'damp-w',
 >> but the same problem persists.
 >> Can anybody Please help me identifying the mistake
 ?
 >> Thank You.
 >> Best Regards,
 >> Vishal Gupta
 >>
 >> B.Tech. 3rd year Mechanical
 >>
 >> Indian Institute of Technology Ropar
 >> Rupnagar (140001), Punjab, India.
 >> Email :- vishal.gupta at iitrpr.ac.in
 >> RMML, IIT Ropar
 >>
 >>
 >>
 >>
 [487a748cedfb942f92401d52262f336d11784524388949.png]
 >>
 >>
 > _______________________________________________
 > Pw_forum mailing list
 > Pw_forum at pwscf.org
 > http://pwscf.org/mailman/listinfo/pw_forum
 >
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 ------------------------------
 
 Message: 8
 Date: Thu, 31 Mar 2016 19:50:08 +0200
 From: Vincenzo Verdolino <vincenzo.verdolino at gmail.com>
 Subject: Re: [Pw_forum] VC_relax
 To: PWSCF Forum <pw_forum at pwscf.org>
 Cc: Ari Paavo Seitsonen <Ari.P.Seitsonen at iki.fi>
 Message-ID: <05BBD120-EEC2-4D57-9DC1-912FCE4A6AB6 at gmail.com>
 Content-Type: text/plain; charset="utf-8"
 
 Dear,
 
 You should try to set the cutoff parameter to higher energy.
 Not sure if you specified the pseudopotential in your
 original email but i would set the parameter initially
 arount 50 Ry. Moreover you should check convergency on this
 number doing single point at different cutoff values and
 making sure your energy converged. Once you get best
 compromize on this parameter make sure your sampling on
 K-POINT is gonverged too. If you still experience issues in
 wf convergency you may want to include occupation=smearing
 (there are several method...try smearing=mv) and play with
 degauss in order to broad the integration for metals
 
 Hope this helps
 
 Vincenzo
 
 Inviato da iPhone
 
 > Il giorno 31 mar 2016, alle ore 19:36, Vishal Gupta
 <vishal.gupta at iitrpr.ac.in>
 ha scritto:
 > 
 > Dear Ari Paavo,
 > Thank you for your informative reply. Can you please
 tell me how to broaden the occupation numbers ?
 > Sorry,  I am a little new at this.
 > Thank you.
 > Best Regards,
 > Vishal
 > 
 > 
 >> On Thu, Mar 31, 2016 at 9:17 PM, Ari P Seitsonen
 <Ari.P.Seitsonen at iki.fi>
 wrote:
 >> 
 >> Dear Vishal Gupta,
 >> 
 >>   Your cut-off energy looks _very_
 low, no matter which elements/pseudo potentials you do
 employ. Probably your system becomes metallic upon the
 relaxation, so I would include some kind of broadening of
 the occupation numbers, in addition possibly using the
 mixing mode 'local-TF', if you have vacuum in your system.
 >> 
 >>     Greetings,
 >> 
 >>        apsi
 >> 
 >>
 -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
 >>   Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi
 / http://www.iki.fi/~apsi/
 >>     Ecole Normale Sup?rieure
 (ENS), D?partement de Chimie, Paris
 >>     Mobile (F) : +33 789 37 24
 25    (CH) : +41 79 71 90 935
 >> 
 >> 
 >> On Thu, 31 Mar 2016, Vishal Gupta wrote:
 >> 
 >>> Hi all,I've been running a vc_relax calculation
 on a 40 atom system. The calculation works fine for some
 >>> 
 >>> cycles. The total force had come down to 0.108.
 After some time. the force started increasing and now the
 >>> iterations don't converge even in 400 steps.
 The input file is
 >>>  /
 >>>  &SYSTEM
 >>>             
           ibrav = 0,
 >>>             
             nat = 40,
 >>>             
            ntyp = 1,
 >>>             
         ecutwfc = 12 ,
 >>>  /
 >>>  &ELECTRONS
 >>>             
     mixing_beta = 0.3 ,
 >>>             
 diagonalization = 'david' ,
 >>>             
 electron_maxstep = 200 ,
 >>>  /
 >>> 
 >>> [&Ions/]
 >>> /
 >>> &CELL
 >>> cell_dynamics= 'sd' ,
 >>> cell_dofree='xy' ,
 >>> /
 >>> 
 >>> CELL_PARAMETERS angstrom
 >>> 
    22.265358047804796   
 0.000000000000000    0.000000000000000
 >>>     
 0.000000000000000   11.131216979724510 
   0.000000000000000
 >>>      0.000000000000000 
  
 0.000000000000000   10.000000000000000
 >>> 
 >>> P.S. Ive tried changing cell dynamics to
 'damp-pr' , 'sd' and 'damp-w', but the same problem
 persists.
 >>> Can anybody Please help me identifying the
 mistake ?
 >>> Thank You.
 >>> Best Regards,
 >>> Vishal Gupta
 >>> 
 >>> B.Tech. 3rd year Mechanical
 >>> 
 >>> Indian Institute of Technology Ropar
 >>> Rupnagar (140001), Punjab, India.
 >>> Email :- vishal.gupta at iitrpr.ac.in
 >>> RMML, IIT Ropar
 >>> 
 >>> 
 >>> 
 >>>
 [487a748cedfb942f92401d52262f336d11784524388949.png]
 >> 
 >> _______________________________________________
 >> Pw_forum mailing list
 >> Pw_forum at pwscf.org
 >> http://pwscf.org/mailman/listinfo/pw_forum
 > 
 > _______________________________________________
 > Pw_forum mailing list
 > Pw_forum at pwscf.org
 > http://pwscf.org/mailman/listinfo/pw_forum
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 ------------------------------
 
 Message: 9
 Date: Thu, 31 Mar 2016 18:03:09 -0500
 From: Yangchuan Li <liyangchuan at utexas.edu>
 Subject: [Pw_forum] Computer do not respond when running
 pwcond
 To: pw_forum at pwscf.org
 Message-ID:
     <CAOqronAUZtsVYchpiv7peXt5GV-Sm1PXoQibiedgBX_qVYeTvQ at mail.gmail.com>
 Content-Type: text/plain; charset="utf-8"
 
 Dear QE users,
 
 I'm using QE version 5.0.2, and I met a situation when
 running pwcond, the
 system did not respond or respond really slow (even moving
 mouse takes
 time), when calculate to this position.
 
 ngper, shell number = 5337 2666
 ngper, n2d = 5337 5337
 
 I'm not sure whether it's doing calculation or not. It
 happens for several
 times and depends on models. Small model works fine. I want
 to ask how this
 happens and is there any method to make sure whether it's
 doing
 calculation? Do I need to kill the run when this happens?
 
 Thanks. Any comment will be appreciated!
 
 Yangchuan Li
 Graduate Research Assistant
 UT Austin | Mechanical Engineering
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