[Pw_forum] negative phonon frequencies for 1-D polymer chain

[ankit jain]

Hello Sanjeev,

The pseudopotentials I am using are
H.pz-vbc.UPF<http://www.quantum-espresso.org/wp-content/uploads/upf_files/H.pz-vbc.UPF>
 and 
C.pz-vbc.UPF<http://www.quantum-espresso.org/wp-content/uploads/upf_files/C.pz-vbc.UPF>


Pseudopotential type: NORMCONS
Method: Von Barth-Car (direct fit)
Functional type: Perdew-Zunger (LDA) exch-corr
scalar relativistic


I have tried kgrid of 1*1*6 and 1*1*12, but both give negative frequencies.



On Mon, Apr 14, 2014 at 12:18 AM, Sanjeev Gupta
wrote:

> what is kind of pseudopotential?
> How much k-point?
>
>
> wishes
> sanjeev
>
>
> On Sun, Apr 13, 2014 at 9:25 AM, Ankit wrote:
>
>> Hello QE developers and users,
>>
>> I am trying to calculate phonon dispersion using ph.x and matdyn.x
>> routines of QE and I am stuck woth negative frequencies for a while now.
>>
>> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
>> The polymer chain is aligned in z-direction and I have added vacuum on
>> x- and y- direction. I did the structure relaxation and I am getting
>> total force after relaxtion as 0.20, which I guess is sufficiently
>> small.
>>
>> After relaxation, when I am trying to calculate phonon dispersion using
>> ph.x and matdyn.x I am getting netting frequencies for some of the
>> phonon modes. I  searched online and on QE mailing list and tried couple
>> of different things:
>>
>> 1. The negative frequencies are appearing for non-gamma point as well,
>> so I guess its not a ASR issue. Anyway, I am using ASR but even after
>> this I am getting negative frequencies.
>> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
>> are very small as suggested on QE FAQs.
>> 3. I checked phonon mode shapes for modes with negative frequencies and
>> they do not look like rotational mode.
>> 4. I tried changing number of k points from 6 to 12 in z direction but
>> this is also not the cause.
>>
>> I am really stuck here and not sure about the cause of negative
>> frequencies. With vc-relax, my structure is getting relaxed which I
>> guess means my structure is stable. But then I am not sure why I am
>> getting negative frequencies.
>>
>> I really appreciate any help or suggestions.
>>
>> Thanks,
>>
>> Ankit Jain
>> IIT Indore,
>> Indore,
>> India
>>
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
> With Best Regards,
>
> 
> Dr. Sanjeev Kumar Gupta
> Fulbright Post-Doctoral Scholar
> Dept. of Physics
> Michigan Technological University
> 1400 Townsend Drive, Houghton
> MI 49931, USA
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[Prasenjit Ghosh]

For which q-point are you getting the imaginary modes? If it is at gamma,
then it may be related to the instability in the structure, if it is at
other q-points, may be lattice parameter is not properly optimized. How
large is the stress you are getting at the end of the vc-relax calculation
(when the code recalculates the total energy, stress and forces with the
optimized lattice parameters & atomic positions). Also have you checked the
convergence of the phonon modes with ecutwfc because typically the phonons
converge much slowly with the size of the basis set than other parameters?

With regards,

Prasenjit


On 13 April 2014 21:55, Ankit  wrote:

> Hello QE developers and users,
>
> I am trying to calculate phonon dispersion using ph.x and matdyn.x
> routines of QE and I am stuck woth negative frequencies for a while now.
>
> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
> The polymer chain is aligned in z-direction and I have added vacuum on
> x- and y- direction. I did the structure relaxation and I am getting
> total force after relaxtion as 0.20, which I guess is sufficiently
> small.
>
> After relaxation, when I am trying to calculate phonon dispersion using
> ph.x and matdyn.x I am getting netting frequencies for some of the
> phonon modes. I  searched online and on QE mailing list and tried couple
> of different things:
>
> 1. The negative frequencies are appearing for non-gamma point as well,
> so I guess its not a ASR issue. Anyway, I am using ASR but even after
> this I am getting negative frequencies.
> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
> are very small as suggested on QE FAQs.
> 3. I checked phonon mode shapes for modes with negative frequencies and
> they do not look like rotational mode.
> 4. I tried changing number of k points from 6 to 12 in z direction but
> this is also not the cause.
>
> I am really stuck here and not sure about the cause of negative
> frequencies. With vc-relax, my structure is getting relaxed which I
> guess means my structure is stable. But then I am not sure why I am
> getting negative frequencies.
>
> I really appreciate any help or suggestions.
>
> Thanks,
>
> Ankit Jain
> IIT Indore,
> Indore,
> India
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
PRASENJIT GHOSH,
IISER Pune,
Dr. Homi Bhabha Road, Pashan
Pune, Maharashtra 411008, India

Phone: +91 (20) 2590 8203
Fax: +91 (20) 2589 9790
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[ankit jain]

Hello Prasenjit,

I am getting negative phonon frequencies for non-gamma points also. After
structure optimization, the total force is 0.20 Ry/au and pressure is
-0.24 kbar.

I am using ecutwfc of 100 Ry, which is converged with respect to the total
energy of the system. I am not able to do convergence with respect to
phonon modes as some modes have negative frequencies. Is there a way to do
ecutwfc convergence for phonon modes without calculating phonon frequencies?

I am atatching my pw.in, ph.in pw.out and ph.out files (which I forgot to
attch in my original mail) here.

Thanks,
ANkit Jain


On Mon, Apr 14, 2014 at 1:29 AM, Prasenjit Ghosh wrote:

> For which q-point are you getting the imaginary modes? If it is at gamma,
> then it may be related to the instability in the structure, if it is at
> other q-points, may be lattice parameter is not properly optimized. How
> large is the stress you are getting at the end of the vc-relax calculation
> (when the code recalculates the total energy, stress and forces with the
> optimized lattice parameters & atomic positions). Also have you checked the
> convergence of the phonon modes with ecutwfc because typically the phonons
> converge much slowly with the size of the basis set than other parameters?
>
> With regards,
>
> Prasenjit
>
>
> On 13 April 2014 21:55, Ankit  wrote:
>
>> Hello QE developers and users,
>>
>> I am trying to calculate phonon dispersion using ph.x and matdyn.x
>> routines of QE and I am stuck woth negative frequencies for a while now.
>>
>> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
>> The polymer chain is aligned in z-direction and I have added vacuum on
>> x- and y- direction. I did the structure relaxation and I am getting
>> total force after relaxtion as 0.20, which I guess is sufficiently
>> small.
>>
>> After relaxation, when I am trying to calculate phonon dispersion using
>> ph.x and matdyn.x I am getting netting frequencies for some of the
>> phonon modes. I  searched online and on QE mailing list and tried couple
>> of different things:
>>
>> 1. The negative frequencies are appearing for non-gamma point as well,
>> so I guess its not a ASR issue. Anyway, I am using ASR but even after
>> this I am getting negative frequencies.
>> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
>> are very small as suggested on QE FAQs.
>> 3. I checked phonon mode shapes for modes with negative frequencies and
>> they do not look like rotational mode.
>> 4. I tried changing number of k points from 6 to 12 in z direction but
>> this is also not the cause.
>>
>> I am really stuck here and not sure about the cause of negative
>> frequencies. With vc-relax, my structure is getting relaxed which I
>> guess means my structure is stable. But then I am not sure why I am
>> getting negative frequencies.
>>
>> I really appreciate any help or suggestions.
>>
>> Thanks,
>>
>> Ankit Jain
>> IIT Indore,
>> Indore,
>> India
>>
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
> PRASENJIT GHOSH,
> IISER Pune,
> Dr. Homi Bhabha Road, Pashan
> Pune, Maharashtra 411008, India
>
> Phone: +91 (20) 2590 8203
> Fax: +91 (20) 2589 9790
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[Prasenjit Ghosh]

Did you try using the acoustic sum rule and see whether the imaginary
frequencies are still there? Also can I have a look at the vc-relax output
file?

Prasenjit


On 14 April 2014 11:10, ankit jain  wrote:

> Hello Prasenjit,
>
> I am getting negative phonon frequencies for non-gamma points also. After
> structure optimization, the total force is 0.20 Ry/au and pressure is
> -0.24 kbar.
>
> I am using ecutwfc of 100 Ry, which is converged with respect to the total
> energy of the system. I am not able to do convergence with respect to
> phonon modes as some modes have negative frequencies. Is there a way to do
> ecutwfc convergence for phonon modes without calculating phonon frequencies?
>
> I am atatching my pw.in, ph.in pw.out and ph.out files (which I forgot to
> attch in my original mail) here.
>
> Thanks,
> ANkit Jain
>
>
> On Mon, Apr 14, 2014 at 1:29 AM, Prasenjit Ghosh  gmail.com>wrote:
>
>> For which q-point are you getting the imaginary modes? If it is at gamma,
>> then it may be related to the instability in the structure, if it is at
>> other q-points, may be lattice parameter is not properly optimized. How
>> large is the stress you are getting at the end of the vc-relax calculation
>> (when the code recalculates the total energy, stress and forces with the
>> optimized lattice parameters & atomic positions). Also have you checked the
>> convergence of the phonon modes with ecutwfc because typically the phonons
>> converge much slowly with the size of the basis set than other parameters?
>>
>> With regards,
>>
>> Prasenjit
>>
>>
>> On 13 April 2014 21:55, Ankit  wrote:
>>
>>> Hello QE developers and users,
>>>
>>> I am trying to calculate phonon dispersion using ph.x and matdyn.x
>>> routines of QE and I am stuck woth negative frequencies for a while now.
>>>
>>> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
>>> The polymer chain is aligned in z-direction and I have added vacuum on
>>> x- and y- direction. I did the structure relaxation and I am getting
>>> total force after relaxtion as 0.20, which I guess is sufficiently
>>> small.
>>>
>>> After relaxation, when I am trying to calculate phonon dispersion using
>>> ph.x and matdyn.x I am getting netting frequencies for some of the
>>> phonon modes. I  searched online and on QE mailing list and tried couple
>>> of different things:
>>>
>>> 1. The negative frequencies are appearing for non-gamma point as well,
>>> so I guess its not a ASR issue. Anyway, I am using ASR but even after
>>> this I am getting negative frequencies.
>>> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
>>> are very small as suggested on QE FAQs.
>>> 3. I checked phonon mode shapes for modes with negative frequencies and
>>> they do not look like rotational mode.
>>> 4. I tried changing number of k points from 6 to 12 in z direction but
>>> this is also not the cause.
>>>
>>> I am really stuck here and not sure about the cause of negative
>>> frequencies. With vc-relax, my structure is getting relaxed which I
>>> guess means my structure is stable. But then I am not sure why I am
>>> getting negative frequencies.
>>>
>>> I really appreciate any help or suggestions.
>>>
>>> Thanks,
>>>
>>> Ankit Jain
>>> IIT Indore,
>>> Indore,
>>> India
>>>
>>>
>>> ___
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>
>>
>>
>>
>> --
>> PRASENJIT GHOSH,
>> IISER Pune,
>> Dr. Homi Bhabha Road, Pashan
>> Pune, Maharashtra 411008, India
>>
>> Phone: +91 (20) 2590 8203
>> Fax: +91 (20) 2589 9790
>>
>> ___
>> 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
>



-- 
PRASENJIT GHOSH,
IISER Pune,
Dr. Homi Bhabha Road, Pashan
Pune, Maharashtra 411008, India

Phone: +91 (20) 2590 8203
Fax: +91 (20) 2589 9790
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[ankit jain]

I have tried acoustic sum rule and it does not change negative frequencies.
I have rerun calculations with several different parameters and seems to
have modified my vc-relax output file. I am re-running it and will send it
as soon as it is done.


On Mon, Apr 14, 2014 at 1:51 AM, Prasenjit Ghosh wrote:

> Did you try using the acoustic sum rule and see whether the imaginary
> frequencies are still there? Also can I have a look at the vc-relax output
> file?
>
> Prasenjit
>
>
> On 14 April 2014 11:10, ankit jain  wrote:
>
>> Hello Prasenjit,
>>
>> I am getting negative phonon frequencies for non-gamma points also. After
>> structure optimization, the total force is 0.20 Ry/au and pressure is
>> -0.24 kbar.
>>
>> I am using ecutwfc of 100 Ry, which is converged with respect to the
>> total energy of the system. I am not able to do convergence with respect to
>> phonon modes as some modes have negative frequencies. Is there a way to do
>> ecutwfc convergence for phonon modes without calculating phonon frequencies?
>>
>> I am atatching my pw.in, ph.in pw.out and ph.out files (which I forgot
>> to attch in my original mail) here.
>>
>> Thanks,
>> ANkit Jain
>>
>>
>> On Mon, Apr 14, 2014 at 1:29 AM, Prasenjit Ghosh > > wrote:
>>
>>> For which q-point are you getting the imaginary modes? If it is at
>>> gamma, then it may be related to the instability in the structure, if it is
>>> at other q-points, may be lattice parameter is not properly optimized. How
>>> large is the stress you are getting at the end of the vc-relax calculation
>>> (when the code recalculates the total energy, stress and forces with the
>>> optimized lattice parameters & atomic positions). Also have you checked the
>>> convergence of the phonon modes with ecutwfc because typically the phonons
>>> converge much slowly with the size of the basis set than other parameters?
>>>
>>> With regards,
>>>
>>> Prasenjit
>>>
>>>
>>> On 13 April 2014 21:55, Ankit  wrote:
>>>
>>>> Hello QE developers and users,
>>>>
>>>> I am trying to calculate phonon dispersion using ph.x and matdyn.x
>>>> routines of QE and I am stuck woth negative frequencies for a while now.
>>>>
>>>> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
>>>> The polymer chain is aligned in z-direction and I have added vacuum on
>>>> x- and y- direction. I did the structure relaxation and I am getting
>>>> total force after relaxtion as 0.20, which I guess is sufficiently
>>>> small.
>>>>
>>>> After relaxation, when I am trying to calculate phonon dispersion using
>>>> ph.x and matdyn.x I am getting netting frequencies for some of the
>>>> phonon modes. I  searched online and on QE mailing list and tried couple
>>>> of different things:
>>>>
>>>> 1. The negative frequencies are appearing for non-gamma point as well,
>>>> so I guess its not a ASR issue. Anyway, I am using ASR but even after
>>>> this I am getting negative frequencies.
>>>> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
>>>> are very small as suggested on QE FAQs.
>>>> 3. I checked phonon mode shapes for modes with negative frequencies and
>>>> they do not look like rotational mode.
>>>> 4. I tried changing number of k points from 6 to 12 in z direction but
>>>> this is also not the cause.
>>>>
>>>> I am really stuck here and not sure about the cause of negative
>>>> frequencies. With vc-relax, my structure is getting relaxed which I
>>>> guess means my structure is stable. But then I am not sure why I am
>>>> getting negative frequencies.
>>>>
>>>> I really appreciate any help or suggestions.
>>>>
>>>> Thanks,
>>>>
>>>> Ankit Jain
>>>> IIT Indore,
>>>> Indore,
>>>> India
>>>>
>>>>
>>>> ___
>>>> Pw_forum mailing list
>>>> Pw_forum at pwscf.org
>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>
>>>
>>>
>>>
>>> --
>>> PRASENJIT GHOSH,
>>> IISER Pune,
>>> Dr. Homi Bhabha Road, Pashan
>>> Pune, Maharashtra 411008, India
>>>
>>> Phone: +91 (20) 2590 8203
>>> Fax: +91 (20) 2589 9790
>>>
>>> ___
>>> 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
>>
>
>
>
> --
> PRASENJIT GHOSH,
> IISER Pune,
> Dr. Homi Bhabha Road, Pashan
> Pune, Maharashtra 411008, India
>
> Phone: +91 (20) 2590 8203
> Fax: +91 (20) 2589 9790
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[ankit jain]

 shapes for modes with negative frequencies
>>>>>> and
>>>>>> they do not look like rotational mode.
>>>>>> 4. I tried changing number of k points from 6 to 12 in z direction but
>>>>>> this is also not the cause.
>>>>>>
>>>>>> I am really stuck here and not sure about the cause of negative
>>>>>> frequencies. With vc-relax, my structure is getting relaxed which I
>>>>>> guess means my structure is stable. But then I am not sure why I am
>>>>>> getting negative frequencies.
>>>>>>
>>>>>> I really appreciate any help or suggestions.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Ankit Jain
>>>>>> IIT Indore,
>>>>>> Indore,
>>>>>> India
>>>>>>
>>>>>>
>>>>>> ___
>>>>>> Pw_forum mailing list
>>>>>> Pw_forum at pwscf.org
>>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> PRASENJIT GHOSH,
>>>>> IISER Pune,
>>>>> Dr. Homi Bhabha Road, Pashan
>>>>> Pune, Maharashtra 411008, India
>>>>>
>>>>> Phone: +91 (20) 2590 8203
>>>>> Fax: +91 (20) 2589 9790
>>>>>
>>>>> ___
>>>>> 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
>>>>
>>>
>>>
>>>
>>> --
>>> PRASENJIT GHOSH,
>>> IISER Pune,
>>> Dr. Homi Bhabha Road, Pashan
>>> Pune, Maharashtra 411008, India
>>>
>>> Phone: +91 (20) 2590 8203
>>> Fax: +91 (20) 2589 9790
>>>
>>> ___
>>> 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
>>
>
>
>
> --
> With Best Regards,
>
> 
> Dr. Sanjeev Kumar Gupta
> Fulbright Post-Doctoral Scholar
> Dept. of Physics
> Michigan Technological University
> 1400 Townsend Drive, Houghton
> MI 49931, USA
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[ankit jain]

 shapes for modes with negative frequencies
>>>>>> and
>>>>>> they do not look like rotational mode.
>>>>>> 4. I tried changing number of k points from 6 to 12 in z direction but
>>>>>> this is also not the cause.
>>>>>>
>>>>>> I am really stuck here and not sure about the cause of negative
>>>>>> frequencies. With vc-relax, my structure is getting relaxed which I
>>>>>> guess means my structure is stable. But then I am not sure why I am
>>>>>> getting negative frequencies.
>>>>>>
>>>>>> I really appreciate any help or suggestions.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Ankit Jain
>>>>>> IIT Indore,
>>>>>> Indore,
>>>>>> India
>>>>>>
>>>>>>
>>>>>> ___
>>>>>> Pw_forum mailing list
>>>>>> Pw_forum at pwscf.org
>>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> PRASENJIT GHOSH,
>>>>> IISER Pune,
>>>>> Dr. Homi Bhabha Road, Pashan
>>>>> Pune, Maharashtra 411008, India
>>>>>
>>>>> Phone: +91 (20) 2590 8203
>>>>> Fax: +91 (20) 2589 9790
>>>>>
>>>>> ___
>>>>> 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
>>>>
>>>
>>>
>>>
>>> --
>>> PRASENJIT GHOSH,
>>> IISER Pune,
>>> Dr. Homi Bhabha Road, Pashan
>>> Pune, Maharashtra 411008, India
>>>
>>> Phone: +91 (20) 2590 8203
>>> Fax: +91 (20) 2589 9790
>>>
>>> ___
>>> 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
>>
>
>
>
> --
> With Best Regards,
>
> 
> Dr. Sanjeev Kumar Gupta
> Fulbright Post-Doctoral Scholar
> Dept. of Physics
> Michigan Technological University
> 1400 Townsend Drive, Houghton
> MI 49931, USA
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[Andrea Dal Corso]

Did you apply the 5.0.3 patch to QE 5.0.2? Without the patch, the phonon
code gives wrong frequencies for some q points. 

HTH,

Andrea


On Mon, 2014-04-14 at 01:19 -0400, ankit jain wrote:
> Hello Sanjeev,
> 
> The pseudopotentials I am using are
> H.pz-vbc.UPF
>  and 
> C.pz-vbc.UPF
> 
> 
> Pseudopotential type: NORMCONS
> Method: Von Barth-Car (direct fit)
> Functional type: Perdew-Zunger (LDA) exch-corr
> scalar relativistic
> 
> 
> I have tried kgrid of 1*1*6 and 1*1*12, but both give negative frequencies.
> 
> 
> 
> On Mon, Apr 14, 2014 at 12:18 AM, Sanjeev Gupta
> wrote:
> 
> > what is kind of pseudopotential?
> > How much k-point?
> >
> >
> > wishes
> > sanjeev
> >
> >
> > On Sun, Apr 13, 2014 at 9:25 AM, Ankit  > gmail.com>wrote:
> >
> >> Hello QE developers and users,
> >>
> >> I am trying to calculate phonon dispersion using ph.x and matdyn.x
> >> routines of QE and I am stuck woth negative frequencies for a while now.
> >>
> >> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
> >> The polymer chain is aligned in z-direction and I have added vacuum on
> >> x- and y- direction. I did the structure relaxation and I am getting
> >> total force after relaxtion as 0.20, which I guess is sufficiently
> >> small.
> >>
> >> After relaxation, when I am trying to calculate phonon dispersion using
> >> ph.x and matdyn.x I am getting netting frequencies for some of the
> >> phonon modes. I  searched online and on QE mailing list and tried couple
> >> of different things:
> >>
> >> 1. The negative frequencies are appearing for non-gamma point as well,
> >> so I guess its not a ASR issue. Anyway, I am using ASR but even after
> >> this I am getting negative frequencies.
> >> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
> >> are very small as suggested on QE FAQs.
> >> 3. I checked phonon mode shapes for modes with negative frequencies and
> >> they do not look like rotational mode.
> >> 4. I tried changing number of k points from 6 to 12 in z direction but
> >> this is also not the cause.
> >>
> >> I am really stuck here and not sure about the cause of negative
> >> frequencies. With vc-relax, my structure is getting relaxed which I
> >> guess means my structure is stable. But then I am not sure why I am
> >> getting negative frequencies.
> >>
> >> I really appreciate any help or suggestions.
> >>
> >> Thanks,
> >>
> >> Ankit Jain
> >> IIT Indore,
> >> Indore,
> >> India
> >>
> >>
> >> ___
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://pwscf.org/mailman/listinfo/pw_forum
> >>
> >
> >
> >
> > --
> > With Best Regards,
> >
> > 
> > Dr. Sanjeev Kumar Gupta
> > Fulbright Post-Doctoral Scholar
> > Dept. of Physics
> > Michigan Technological University
> > 1400 Townsend Drive, Houghton
> > MI 49931, USA
> > 
> >
> > ___
> > 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

-- 
Andrea Dal CorsoTel. 0039-040-3787428
SISSA, Via Bonomea 265  Fax. 0039-040-3787249
I-34136 Trieste (Italy) e-mail: dalcorso at sissa.it

[Pw_forum] Too big atomic spheres error

[raha khalili]

Dear PW users

I am trying to calculate transmission coefficient of a molecular wire
using espresso-5.0.2. The output returns with the error

%%
 Error in routine init_orbitals (1):
 Too big atomic spheres
 %%

Below is the input for scf calculation and pwcond.x:

&control
calculation = 'scf'
restart_mode='from_scratch',
prefix='adn',
tprnfor = .true.
pseudo_dir = '/home/khalili/espresso-5.0.2/pseudo',
outdir='./'
 /
 &system
ibrav= 0, celldm(1)=5.613142761,
nat= 21, ntyp= 5,
ecutwfc = 27,
ecutrho = 391,
occupations='smearing', smearing='marzari-vanderbilt', degauss=0.05
lspinorb=.true.
noncolin = .true.
 /
 &electrons
diagonalization='david'
electron_maxstep = 500,
mixing_mode = 'plain'
mixing_beta = 0.3
conv_thr =  1.0d-7
/
ATOMIC_SPECIES
 C   12.0107   C.pz-rrkjus.UPF
 H   1.0   H.pz-rrkjus.UPF
 N   14.0067   N.pz-rrkjus.UPF
 S   32.065S.pz-n-rrkjus_psl.0.1.UPF
 Au  196.966   Au.rel-pz-dn-rrkjus_psl.0.1.UPF
ATOMIC_POSITIONS
...
CELL_PARAMETERS cubic
 5.613142761   0.0   0.0
 0.0   5.613142761   0.0
 0.0   0.0   5.613142761
K_POINTS {Automatic}
 1 1 4 1 1 1

&INPUTCOND
outdir = './',
prefixt = 'adn',
tran_file = 'trans.AdnAu',
ikind = 1,
energy0 = 1.d0,
denergy=-0.4d0,
ewind=1.d0,
epsproj=1.d-3,
nz1 = 1,
 /
1
0.0  0.0  1.0
100

I appreciate any help.

Regards

Khadije Khalili

Ph.D Student of Solid-State Physics
Department of Physics
University of Mazandaran
Babolsar, Iran
kh.khalili at stu.umz.ac.ir
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[Pw_forum] espresso-5.0.2 error when testing modules

[薛诗川]

Hi,all,

I am testing espresso-5.0.2. When I test some of its modules(e.g. CPV,
PWCOND , PP??),I encountered some questions.

1.   when testing CPV/examples/example09, for input
*mgo.cp.damp.efield,*there is an error:

Error in routine ortho (31):

max number of iterations exceeded

2.   when testing CPV/examples/example05, there is an error:

Error in routine cp_read_cell (5):

cannot open restart file for reading:
/root/tmp//h2o_mol_50.save/data-file.xml

however, these files should be produced during the process under out_dir,
why is it wrong with such an error : cannot  find file?

3.   Phonon/examples/example01

The same with 2 that files under out_dir are not found.

4.   When testing PP/examples/example01, error:

from bands : error # 1

gamma_only case not implemented



thanks a lot
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[Pw_forum] Too big atomic spheres error

[Gabriele Sclauzero]

Dear Khadije,

 If you withheld the atomic positions is difficult to understand 
your problem and give suggestions. I guess the one below is the 
scattering region. What about the leads? If you specify prefixt, then 
you need to use bdl to compute transmission (assuming that your cell 
also contains the leads).

Are you sure you have understood the setup for a transmission calculation?
I would strongly suggest you to go through examples 1 and 2 in 
PWCOND/examples and make sure you understand them.
Then you can go back to your system. Also, I would suggest to start with 
the collinear calculation, because calculations including spin-orbit are 
much more costly and you might just waste a lot of computer time if you 
are not sure of what you are doing.

HTH

GS

On 04/14/2014 10:08 AM, raha khalili wrote:
> Dear PW users
>
> I am trying to calculate transmission coefficient of a molecular wire using 
> espresso-5.0.2. The output returns with the error
> %%
>  Error in routine init_orbitals (1):
>  Too big atomic spheres
>  %%
> Below is the input for scf calculation and pwcond.x:
> &control
>  calculation = 'scf'
>  restart_mode='from_scratch',
>  prefix='adn',
>  tprnfor = .true.
>  pseudo_dir = '/home/khalili/espresso-5.0.2/pseudo',
>  outdir='./'
>   /
>   &system
>  ibrav= 0, celldm(1)=5.613142761,
>  nat= 21, ntyp= 5,
>  ecutwfc = 27,
>  ecutrho = 391,
>  occupations='smearing', smearing='marzari-vanderbilt', degauss=0.05
>  lspinorb=.true.
>  noncolin = .true.
>   /
>   &electrons
>  diagonalization='david'
>  electron_maxstep = 500,
>  mixing_mode = 'plain'
>  mixing_beta = 0.3
>  conv_thr =  1.0d-7
> /
> ATOMIC_SPECIES
>   C   12.0107   C.pz-rrkjus.UPF
>   H   1.0   H.pz-rrkjus.UPF
>   N   14.0067   N.pz-rrkjus.UPF
>   S   32.065S.pz-n-rrkjus_psl.0.1.UPF
>   Au  196.966   Au.rel-pz-dn-rrkjus_psl.0.1.UPF
> ATOMIC_POSITIONS
> ...
> CELL_PARAMETERS cubic
>   5.613142761   0.0   0.0
>   0.0   5.613142761   0.0
>   0.0   0.0   5.613142761
> K_POINTS {Automatic}
>   1 1 4 1 1 1
> &INPUTCOND
>  outdir = './',
>  prefixt = 'adn',
>  tran_file = 'trans.AdnAu',
>  ikind = 1,
>  energy0 = 1.d0,
>  denergy=-0.4d0,
>  ewind=1.d0,
>  epsproj=1.d-3,
>  nz1 = 1,
>   /
>  1
>  0.0  0.0  1.0
>  100
> I appreciate any help.
> Regards
> Khadije Khalili
> Ph.D Student of Solid-State Physics
> Department of Physics
> University of Mazandaran
> Babolsar, Iran
> kh.khalili at stu.umz.ac.ir <mailto:kh.khalili at stu.umz.ac.ir>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum


-- 
Dr. Gabriele Sclauzero
ETH Zurich
Materials Theory
HIT G 43.2
Wolfgang-Pauli-Str. 27
8093 Z?rich, Switzerland

Phone +41 44 633 94 10
Fax +41 44 633 14 59
gabriele.sclauzero at mat.ethz.ch
http://www.theory.mat.ethz.ch/people/postdocs/gsclauze

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[Pw_forum] bad Fermi energy

[Tommaso Francese]

Dear Colleagues, 
i know that this problem was faced in recent posts, but, even if i tried to 
follow every suggest, i0m not able to run a ?nscf? calculation about a cubic 
zirconia.
My input file is:
 &CONTROL
 calculation = 'nscf' ,
  outdir = '/home/+/QE/espresso-5.0.2/tmp/' ,
  pseudo_dir = '/home/+/upf_files/' ,
  prefix = 'zr' ,
 /
 &SYSTEM
   ibrav = 1,
   celldm(1) = 5.1454,
 nat = 12,
ntyp = 2,
 ecutwfc = 22.05 ,
nbnd = 12,
 occupations = 'tetrahedra' ,
exxdiv_treatment = 'gygi-baldereschi' ,
 /
 &ELECTRONS
 /
ATOMIC_SPECIES
   Zr   91.22400  Zr.pw91-nsp-van.UPF 
O   15.99900  O.pw91-van_ak.UPF 
ATOMIC_POSITIONS angstroms 
   Zr  0.00.00.0
O  0.250000.250000.25000
O  0.750000.750000.25000
O  0.750000.250000.75000
O  0.250000.750000.75000
O  0.250000.250000.75000
O  0.750000.750000.75000
O  0.250000.750000.25000
O  0.750000.250000.25000
   Zr  0.00.50.5
   Zr  0.50.00.5
   Zr  0.50.50.0
K_POINTS automatic 
  10 10 10   1 1 1 

where i make a mistake? can someone help me? i need to calculate the DOS e band 
structure, but the code doesn?t run.
Thanks a lot, 
Tommaso, Universit? C? Foscari of Venice.
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[Pw_forum] Too big atomic spheres error

[raha khalili]

Dear Dr. Sclauzero

Thanks a lot for your help and suggestion. I studied mentioned examples and
changed my input files. I separated electrodes in another file with
prefix='au', molecule with prefix='adn' and pwcond.x with prefixl='au',
prefixs='adn' and prefixs='au'. Could you tell if I am in right way, please?





On Mon, Apr 14, 2014 at 5:04 PM, Gabriele Sclauzero <
gabriele.sclauzero at mat.ethz.ch> wrote:

>  Dear Khadije,
>
> If you withheld the atomic positions is difficult to understand your
> problem and give suggestions. I guess the one below is the scattering
> region. What about the leads? If you specify prefixt, then you need to use
> bdl to compute transmission (assuming that your cell also contains the
> leads).
>
> Are you sure you have understood the setup for a transmission calculation?
> I would strongly suggest you to go through examples 1 and 2 in
> PWCOND/examples and make sure you understand them.
> Then you can go back to your system. Also, I would suggest to start with
> the collinear calculation, because calculations including spin-orbit are
> much more costly and you might just waste a lot of computer time if you are
> not sure of what you are doing.
>
> HTH
>
> GS
>
>
> On 04/14/2014 10:08 AM, raha khalili wrote:
>
> Dear PW users
>
>  I am trying to calculate transmission coefficient of a molecular wire using 
> espresso-5.0.2. The output returns with the error
>
>  %%
>   Error in routine init_orbitals (1):
>  Too big atomic spheres
>  %%
>
> Below is the input for scf calculation and pwcond.x:
>
> &control
> calculation = 'scf'
> restart_mode='from_scratch',
> prefix='adn',
> tprnfor = .true.
> pseudo_dir = '/home/khalili/espresso-5.0.2/pseudo',
> outdir='./'
>  /
>  &system
> ibrav= 0, celldm(1)=5.613142761,
> nat= 21, ntyp= 5,
> ecutwfc = 27,
> ecutrho = 391,
> occupations='smearing', smearing='marzari-vanderbilt', degauss=0.05
> lspinorb=.true.
> noncolin = .true.
>  /
>  &electrons
> diagonalization='david'
> electron_maxstep = 500,
> mixing_mode = 'plain'
> mixing_beta = 0.3
> conv_thr =  1.0d-7
> /
> ATOMIC_SPECIES
>  C   12.0107   C.pz-rrkjus.UPF
>  H   1.0   H.pz-rrkjus.UPF
>  N   14.0067   N.pz-rrkjus.UPF
>  S   32.065S.pz-n-rrkjus_psl.0.1.UPF
>  Au  196.966   Au.rel-pz-dn-rrkjus_psl.0.1.UPF
> ATOMIC_POSITIONS
> ...
> CELL_PARAMETERS cubic
>  5.613142761   0.0   0.0
>  0.0   5.613142761   0.0
>  0.0   0.0   5.613142761
> K_POINTS {Automatic}
>  1 1 4 1 1 1
>
> &INPUTCOND
> outdir = './',
> prefixt = 'adn',
> tran_file = 'trans.AdnAu',
> ikind = 1,
> energy0 = 1.d0,
> denergy=-0.4d0,
> ewind=1.d0,
> epsproj=1.d-3,
> nz1 = 1,
>  /
> 1
> 0.0  0.0  1.0
> 100
>
> I appreciate any help.
>
> Regards
>
> Khadije Khalili
>
>  Ph.D Student of Solid-State Physics
> Department of Physics
> University of Mazandaran
> Babolsar, Iran
> kh.khalili at stu.umz.ac.ir
>
>
>
> ___
> Pw_forum mailing listPw_forum at 
> pwscf.orghttp://pwscf.org/mailman/listinfo/pw_forum
>
>
>
> --
> Dr. Gabriele Sclauzero
> ETH Zurich
> Materials Theory
> HIT G 43.2
> Wolfgang-Pauli-Str. 27
> 8093 Z?rich, Switzerland
>
> Phone +41 44 633 94 10
> Fax +41 44 633 14 59gabriele.sclauzero at 
> mat.ethz.chhttp://www.theory.mat.ethz.ch/people/postdocs/gsclauze
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
Khadije Khalili
Ph.D Student of Solid-State Physics
Department of Physics
University of Mazandaran
Babolsar, Iran
kh.khalili at stu.umz.ac.ir
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[Pw_forum] Too big atomic spheres error

[Sclauzero Gabriele]

Dear Dr. Sclauzero

Thanks a lot for your help and suggestion. I studied mentioned examples and 
changed my input files. I separated electrodes in another file with 
prefix='au', molecule with prefix='adn' and pwcond.x with prefixl='au', 
prefixs='adn'

So fast! Please have a look at Alexander's notes too:
http://iramis.cea.fr/Pisp/alexander.smogunov/PWCOND/lectures.pdf


and prefixs='au'.

Did you mean prefixr='au'?
Anyway, if you use ikind=1 (identical leads) you just need prefixl and prefixs.

Now you need to check che complex band structure of your lead (with ikind=0 for 
prefixl='au').
Then compare it to the one of the left part of the scattering cell (which must 
incorporata an "extension" of the lead leads on both sides) by using prefixt 
and bdl (again with ikind=0).



Could you tell if I am in right way, please?






Dr. Gabriele Sclauzero
Materials Theory - ETHZ
ETH Zurich, HIT G 43.2
Wolfgang-Pauli-Str. 27
8093 Z?rich, Switzerland

Phone +41 44 633 94 10
Fax +41 44 633 14 59
gabriele.sclauzero at mat.ethz.ch
www.theory.mat.ethz.ch

[Pw_forum] Too big atomic spheres error

[raha khalili]

Dear Dr. Sclauzero

I appreciate your reply. It is so helpful.

Best Regards
Khadije


On Mon, Apr 14, 2014 at 6:11 PM, Sclauzero Gabriele <
gabriele.sclauzero at mat.ethz.ch> wrote:

>
>
>
>
>
>
> Dear Dr. Sclauzero
>
> Thanks a lot for your help and suggestion. I studied mentioned examples
> and changed my input files. I separated electrodes in another file with
> prefix='au', molecule with prefix='adn' and pwcond.x with prefixl='au',
> prefixs='adn'
>
> So fast! Please have a look at Alexander's notes too:
> http://iramis.cea.fr/Pisp/alexander.smogunov/PWCOND/lectures.pdf
>
>
> and prefixs='au'.
>
> Did you mean prefixr='au'?
> Anyway, if you use ikind=1 (identical leads) you just need prefixl and
> prefixs.
>
> Now you need to check che complex band structure of your lead (with
> ikind=0 for prefixl='au').
> Then compare it to the one of the left part of the scattering cell (which
> must incorporata an "extension" of the lead leads on both sides) by using
> prefixt and bdl (again with ikind=0).
>
>
>
> Could you tell if I am in right way, please?
>
>
>
>
>
>
> Dr. Gabriele Sclauzero
> Materials Theory - ETHZ
> ETH Zurich, HIT G 43.2
> Wolfgang-Pauli-Str. 27
> 8093 Z?rich, Switzerland
>
> Phone +41 44 633 94 10
> Fax +41 44 633 14 59
> gabriele.sclauzero at mat.ethz.ch<mailto:gabriele.sclauzero at mat.ethz.ch>
> www.theory.mat.ethz.ch
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
Khadije Khalili
Ph.D Student of Solid-State Physics
Department of Physics
University of Mazandaran
Babolsar, Iran
kh.khalili at stu.umz.ac.ir
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[ankit jain]

Hello Andrea,

I am not using 5.0.3 patch to QE 5.0.2 right now and I guess this is the
issue. I will try using it today and will see how things go.

Thanks a lot,
Ankit Jain


On Mon, Apr 14, 2014 at 3:24 AM, Andrea Dal Corso  wrote:

> Did you apply the 5.0.3 patch to QE 5.0.2? Without the patch, the phonon
> code gives wrong frequencies for some q points.
>
> HTH,
>
> Andrea
>
>
> On Mon, 2014-04-14 at 01:19 -0400, ankit jain wrote:
> > Hello Sanjeev,
> >
> > The pseudopotentials I am using are
> > H.pz-vbc.UPF<
> http://www.quantum-espresso.org/wp-content/uploads/upf_files/H.pz-vbc.UPF>
> >  and C.pz-vbc.UPF<
> http://www.quantum-espresso.org/wp-content/uploads/upf_files/C.pz-vbc.UPF>
> >
> >
> > Pseudopotential type: NORMCONS
> > Method: Von Barth-Car (direct fit)
> > Functional type: Perdew-Zunger (LDA) exch-corr
> > scalar relativistic
> >
> >
> > I have tried kgrid of 1*1*6 and 1*1*12, but both give negative
> frequencies.
> >
> >
> >
> > On Mon, Apr 14, 2014 at 12:18 AM, Sanjeev Gupta
> > wrote:
> >
> > > what is kind of pseudopotential?
> > > How much k-point?
> > >
> > >
> > > wishes
> > > sanjeev
> > >
> > >
> > > On Sun, Apr 13, 2014 at 9:25 AM, Ankit  >wrote:
> > >
> > >> Hello QE developers and users,
> > >>
> > >> I am trying to calculate phonon dispersion using ph.x and matdyn.x
> > >> routines of QE and I am stuck woth negative frequencies for a while
> now.
> > >>
> > >> I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
> > >> The polymer chain is aligned in z-direction and I have added vacuum on
> > >> x- and y- direction. I did the structure relaxation and I am getting
> > >> total force after relaxtion as 0.20, which I guess is sufficiently
> > >> small.
> > >>
> > >> After relaxation, when I am trying to calculate phonon dispersion
> using
> > >> ph.x and matdyn.x I am getting netting frequencies for some of the
> > >> phonon modes. I  searched online and on QE mailing list and tried
> couple
> > >> of different things:
> > >>
> > >> 1. The negative frequencies are appearing for non-gamma point as well,
> > >> so I guess its not a ASR issue. Anyway, I am using ASR but even after
> > >> this I am getting negative frequencies.
> > >> 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I
> guess
> > >> are very small as suggested on QE FAQs.
> > >> 3. I checked phonon mode shapes for modes with negative frequencies
> and
> > >> they do not look like rotational mode.
> > >> 4. I tried changing number of k points from 6 to 12 in z direction but
> > >> this is also not the cause.
> > >>
> > >> I am really stuck here and not sure about the cause of negative
> > >> frequencies. With vc-relax, my structure is getting relaxed which I
> > >> guess means my structure is stable. But then I am not sure why I am
> > >> getting negative frequencies.
> > >>
> > >> I really appreciate any help or suggestions.
> > >>
> > >> Thanks,
> > >>
> > >> Ankit Jain
> > >> IIT Indore,
> > >> Indore,
> > >> India
> > >>
> > >>
> > >> ___
> > >> Pw_forum mailing list
> > >> Pw_forum at pwscf.org
> > >> http://pwscf.org/mailman/listinfo/pw_forum
> > >>
> > >
> > >
> > >
> > > --
> > > With Best Regards,
> > >
> > > 
> > > Dr. Sanjeev Kumar Gupta
> > > Fulbright Post-Doctoral Scholar
> > > Dept. of Physics
> > > Michigan Technological University
> > > 1400 Townsend Drive, Houghton
> > > MI 49931, USA
> > > 
> > >
> > > ___
> > > 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
>
> --
> Andrea Dal CorsoTel. 0039-040-3787428
> SISSA, Via Bonomea 265  Fax. 0039-040-3787249
> I-34136 Trieste (Italy) e-mail: dalcorso at sissa.it
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] negative phonon frequencies for 1-D polymer chain

[Ankit]

Thanks a lot Andrea. I just checked it and it solved the issue. 
Frequencies are all non-negative now.

Thank You,
Ankit Jain

On 04/14/2014 03:24 AM, Andrea Dal Corso wrote:
> Did you apply the 5.0.3 patch to QE 5.0.2? Without the patch, the phonon
> code gives wrong frequencies for some q points.
>
> HTH,
>
> Andrea
>
>
> On Mon, 2014-04-14 at 01:19 -0400, ankit jain wrote:
>> Hello Sanjeev,
>>
>> The pseudopotentials I am using are
>> H.pz-vbc.UPF
>>   and 
>> C.pz-vbc.UPF
>>
>>
>> Pseudopotential type: NORMCONS
>> Method: Von Barth-Car (direct fit)
>> Functional type: Perdew-Zunger (LDA) exch-corr
>> scalar relativistic
>>
>>
>> I have tried kgrid of 1*1*6 and 1*1*12, but both give negative frequencies.
>>
>>
>>
>> On Mon, Apr 14, 2014 at 12:18 AM, Sanjeev Gupta
>> wrote:
>>
>>> what is kind of pseudopotential?
>>> How much k-point?
>>>
>>>
>>> wishes
>>> sanjeev
>>>
>>>
>>> On Sun, Apr 13, 2014 at 9:25 AM, Ankit >> gmail.com>wrote:
>>>
 Hello QE developers and users,

 I am trying to calculate phonon dispersion using ph.x and matdyn.x
 routines of QE and I am stuck woth negative frequencies for a while now.

 I have a 1-D chain of polyethylene which has 6 atoms in the unit-cell.
 The polymer chain is aligned in z-direction and I have added vacuum on
 x- and y- direction. I did the structure relaxation and I am getting
 total force after relaxtion as 0.20, which I guess is sufficiently
 small.

 After relaxation, when I am trying to calculate phonon dispersion using
 ph.x and matdyn.x I am getting netting frequencies for some of the
 phonon modes. I  searched online and on QE mailing list and tried couple
 of different things:

 1. The negative frequencies are appearing for non-gamma point as well,
 so I guess its not a ASR issue. Anyway, I am using ASR but even after
 this I am getting negative frequencies.
 2. I reduced my tr2_ph and conv_thr to 1.0d-14 and 1.0d-15 which I guess
 are very small as suggested on QE FAQs.
 3. I checked phonon mode shapes for modes with negative frequencies and
 they do not look like rotational mode.
 4. I tried changing number of k points from 6 to 12 in z direction but
 this is also not the cause.

 I am really stuck here and not sure about the cause of negative
 frequencies. With vc-relax, my structure is getting relaxed which I
 guess means my structure is stable. But then I am not sure why I am
 getting negative frequencies.

 I really appreciate any help or suggestions.

 Thanks,

 Ankit Jain
 IIT Indore,
 Indore,
 India


 ___
 Pw_forum mailing list
 Pw_forum at pwscf.org
 http://pwscf.org/mailman/listinfo/pw_forum

>>>
>>>
>>> --
>>> With Best Regards,
>>>
>>> 
>>> Dr. Sanjeev Kumar Gupta
>>> Fulbright Post-Doctoral Scholar
>>> Dept. of Physics
>>> Michigan Technological University
>>> 1400 Townsend Drive, Houghton
>>> MI 49931, USA
>>> 
>>>
>>> ___
>>> 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

[Pw_forum] espresso-5.0.2 error when testing modules

[Fabricio Cannini]

Em 14-04-2014 13:51, ??? escreveu:

Hi there.

> 2.For PP/examples, still the same error: gamma_only case not implemented

IIRC, this was fixed in 5.0.3 .

I'm afraid i can't answer your other questions.

> I don?t know its specific reasons.
>
> 3.For testfiles under PWCOND, there is one common error:
>
> task # 3
>
> from gep_x : error #82
>
> error on zggev
>
> really need your help
>
> thanks
>
> below are my files.

[Pw_forum] copper norm-conserving pseudopotential

[Amin Torabi]

Hi there,

Why isn't there any norm-conserving pseudopotential for copper in the
nc_ps_collection.job file of the pslibrary package?
Can anyone spare me one? Thanks!


-- 
**
Amin Torabi
Ph.D. Candidate
Department of Chemistry
University of Western Ontario
**
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[Pw_forum] bad Fermi energy

[Paolo Giannozzi]

On Mon, 2014-04-14 at 14:38 +0200, Tommaso Francese wrote:

> i need to calculate the DOS e band structure, but the code 
> doesn?t run.

"it doesn't run" is not a sufficient description

P.
-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222