Re: [Pw_forum] Negative frequency in phonon calculation

The reason of negative frequencies are : 1. Look you pseudopotential perhaps use another and see. 2. Your structure is not well optimized. and many... wishes sanjeev On Sun, Dec 13, 2015 at 8:02 PM, Barnali Bhattacharya < barnalidgbh...@gmail.com> wrote: > Dear Sir/Madam > > > > I am a

Re: [Pw_forum] problem

what is "problem"? thanks sanjeev On Wed, Jul 8, 2015 at 11:18 AM, Surykant Mishra wrote: > Sir, > I am a phd scholar from India, Sir i am getting problem while installing > "Quantum Espresso" so kindly help me for installation of the same.. > > Thank You > >

Re: [Pw_forum] (no subject)

hello, monolayer is 2D structure hence it need 4*4*1. On Wed, Jul 1, 2015 at 3:56 PM, ashkan shekaari wrote: > Dear users > Does the 4*4*4 q mesh result in values different from 4*4*1 for a > monolayer? > Which is true or more exact? > > Kind regards > Ashkan Shekaari >

Re: [Pw_forum] regarding supercells in graphene nanoribbons

Hi, SP perhaps positions of atom is not correct and they repeat in second layers, but again with Giovanni reply, share your input so user look and comment correctly. SKG On Tue, Jun 16, 2015 at 8:16 PM, Surender Pratap < suren1986dhala...@gmail.com> wrote: > Thanks a lot sir,i have taken width

Re: [Pw_forum] about GGA+U calculation

Dear Bipul. One way is that first you perform without U calculation and later you do with U and take difference. So, might be you will information what you want. I am not sure I am right, but try.. thanks and regards sanjeev On Tue, Dec 23, 2014 at 9:11 PM, Bipul Rakshit

Re: [Pw_forum] Bonding nature Na-C

Hi, you may perform the charge calculation and look insight. thanks sanjeev On Tue, Nov 25, 2014 at 5:17 AM, Barnali Bhattacharya < barnalidgbh...@gmail.com> wrote: > Dear QE user, > > I am doing some calculation with sodium absorbed graphene. I want to see > whether the Na-C bond is more

[Pw_forum] PW.X WORKS ONCE AND NEXT TIME DOESN'T.. FOR THE SAME INPUT FILE..

Hi The file graphene.scf20.out is not showing any error message. On Mon, Jul 14, 2014 at 5:01 AM, siddheshwar chopra wrote: > Dear Users, > I ran the pw.x successfully using 4 processors. But again when I am > running the same i/p file, I am getting this error: > > >

[Pw_forum] phononi

Hello Only looking figure, we can not say. plz post your input and output. bests sanjeev On Fri, Jul 4, 2014 at 6:20 PM, Masoud Avi wrote: > Hi, dear all > I did run the phonon, and there is the problem in result. the part of > optic is unusual. Image've attached it. > please help me > >

[Pw_forum] Reg: To calculate EOS using Quantum espresso.

yes, it is bulk modulus. On Sat, May 31, 2014 at 8:33 PM, Peram sreenivasa reddy < peramsreenivas at gmail.com> wrote: > Dear Paolo Giannozz Sir, > > Thank you very much for your replay. > > I gone thorough the the ev.f90 file. > > My system is cubic. I created the input file according to the

[Pw_forum] Reg: To calculate EOS using Quantum espresso.

plz write a small code and can calculate the things. and look theory: http://en.wikipedia.org/wiki/Equation_of_state bests sanjeev On Thu, May 29, 2014 at 12:11 AM, Peram sreenivasa reddy < peramsreenivas at gmail.com> wrote: > Dear PWSCF Forum, > >I want to calculate the equation of state

[Pw_forum] Regarding Phonon dispersions

Hi Can u provide your SCF input file? Bests sanjeev On Fri, Apr 25, 2014 at 7:04 AM, Kondaiah Samudrala wrote: > Dear all, > > Can anyone perform Phonon dispersions with LO-TO splitting for body > centerd tetragonal structure with Quantum espresso??. > > I am sure and did LO-TO spllitting

[Pw_forum] phonon parallelism

Hi can u follow this link: http://users.ictp.it/~pub_off/lectures/lns024/10-giannozzi/10-giannozzi.pdf bests sanjeev On Wed, Apr 16, 2014 at 3:46 AM, Uri Argaman wrote: > Dear QE users > I'm doing a phonon calculation with 4 q-points in each direction in > hexagonal lattice. As a result, the

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

good. can you take one more test to change the pseudo and see. May be I am wrong but see. On Sun, Apr 13, 2014 at 11:02 PM, ankit jain wrote: > I have tried acoustic sum rule and it does not change negative > frequencies. > I have rerun calculations with several different parameters and

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

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. >

[Pw_forum] Convergence problem for relax calculation

as suggested by other. try to consider metallic nature and use different value of degauss and see plot of total energy. hopefully, it will work! enjoy sanjeev On Thu, Mar 6, 2014 at 12:27 PM, Bramha Pandey wrote: > Hi Mitul, > As Prof. Paolo has pointed out that this system shows nature of

[Pw_forum] Bulk modulus calculation

Hi For bulk modulus, energy Vs lattice const., is always welcome. Otherway, there are lot of discussions on PWSCF forum, as one of by Prof. Eduardo Menendez. http://exciting.wdfiles.com/local--files/lithium-energy-vs-strain-calculations/elastic-paper.pdf and http://exciting-code.org/elastic

[Pw_forum] forming super cell - reg.,

Dear Muthu Plz follow the following link: http://qe-forge.org/pipermail/pw_forum/2009-April/087059.html there is plenty ways to create supercell. bests sanjeev On Tue, Jan 21, 2014 at 5:27 PM, Muthu V wrote: > Dear QE users > > i want to create supercell of Si and iO2 from their unitcell. i

[Pw_forum] thin film

in addition, you can use many graphical packages or better way use xcrysden and define the unit cell and then play around it. Further, I would like to say read first solid state physics book for it. bests sanjeev On Mon, Nov 18, 2013 at 5:12 PM, Yue-Wen Fang wrote: > You can try to use pwgui

[Pw_forum] vc-relax calculation

can you post the error? bests sanjeev On Sun, Nov 10, 2013 at 11:43 AM, ehsan targholi wrote: > > *hi* > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > *dear all, thanks for reply to my earlier question. i

[Pw_forum] Phonon dispersion

Hi Use Xcrysden to generate the q-points. thanks sanjeev On Thu, Oct 3, 2013 at 8:46 AM, Chukwuemeka Okoye wrote: > Dear Users, > > I need your assistance to enable me generate the q-points along the path > for say, a bcc structure, > for use in calculating the phonon frequencies i.e in

[Pw_forum] phonon calculation with no convergence

It is common problem, please try to look FAQ from the website. Further, one possible help to use alpha_mix and nmix_ph, may solve your problem. Bests S On Thu, May 30, 2013 at 6:45 PM, wrote: > Dear all, > I am doing phonon calculation. > and it ends with error "No convergence has been

[Pw_forum] Getting NaN values in QHA calculations

Dear Peram, I am suspecting some imaginary frequencies in .fc file may lead to NaN. Another issue may be not complied correctly. Did you tried the reproduce the result another machine? did you got same error? Looking to see your mail, it indicate something missing: mv: cannot stat

[Pw_forum] primitive cell for slab calc

Dear Vijaya, On Tue, May 28, 2013 at 7:51 AM, vijaya subramanian wrote: > Hi > For a slab calculation I use ibrav=0 and set up my unit cell > such that the last row and column of atoms is omitted. > When using xcrysden I see no overlapping atoms and > am able to get extended cells with the

[Pw_forum] "Raman activities" do not converge

Dear Wang In my guess, the converging mostly depends on choosing pseudopotential, so may be it is the problem, that you are not getting converge Raman activity. Otherhand, can you check your structure as well as, but i am not sure. Best Sanjeev On Wed, May 29, 2013 at 5:22 AM, xirainbow

[Pw_forum] phonon properties

It is better to read first PWSCF documents as well as see the tutorials like: http://www.quantum-espresso.org/?page_id=42, and follow the activity like http://cdsagenda5.ictp.trieste.it/html_trees_links/1590597488/ Bests Sanjeev On Sun, Mar 10, 2013 at 7:58 AM, Shiva Mokhavat wrote: > dear all

[Pw_forum] EELNE Spectra

Dear PWSCF users I am interested to calculated the Electron Energy Loss Near-Edge Fine spectra. I would like to know weather PWSCF can calculate? suggest. Best Regards Sanjeev -- Dept. of Physics Michigan Technological University 1400 Townsend Drive Houghton MI 49931, USA --

[Pw_forum] Compute Debye temperature

Please do not mail again -again. 1. with PWSCF package, find utility QHA, read and install. see this post: http://www.democritos.it/pipermail/pw_forum/2011-October/022205.html. I also suggest, please read this good article also, http://arxiv.org/abs/1112.4977v1 Further, read solid state Physics,

[Pw_forum] Efermi in band structure calculations

you have to give small smearing. best SKG On Thu, Nov 29, 2012 at 9:54 AM, C wrote: > hm... there is no 'Fermi' in scf.out file > > and therefore grep Fermi scf.out (of course I use here the file name used > in my calculations) > does not give me anything > > maybe I need to add some

[Pw_forum] Density of states

Yes, no further change is required. best skg On Sun, Sep 16, 2012 at 8:15 AM, Sohail Ahmad wrote: > > Dear QE Users > > I am trying to find DOS for MoS using version 5.0.1 > > I have already done this using version 4.2.1 around one month back > > The only difference i noticed that i have to

[Pw_forum] from frc_blk : error #

Dear PWSCF user Greetings *For Phonon calculation:* After successfully running q2r.in. But matdyn.in running amass(1)=65.409, amass(2)=15.9994, asr='crystal', flfrc='zno.fc', flfrq='zno.freq' / ... . I am getting this error like this

[Pw_forum] LDA+U with phonon

Dear PWSCF users. I would like to know the present status of use LDA+U in phonon calculation. Further, the problem in rare-earth materials due to f-electron need justification, how we overcome this issue in phonon calculations? Please suggest me. Best Regards Sanjeev -- *Dr. Sanjeev Kumar

[Pw_forum] vc-relax for a Magnetic atom

Dear Ali, It is bad habit. This is forum, where you can put input file, so expert can find the mistake. Another, thing it is good if you provide your affiliation, so we can know whom i am talking. My best suggestion, read tutorial and do examples. Really very helpful. Thanks Sanjeev On Wed,

[Pw_forum] Raman spectra calculation using QE

see the examples of espresso. there u can find the answer of your question. wishes SKG On Tue, Nov 1, 2011 at 9:56 AM, bhabya sahoo wrote: > can u explain me the procedure for calculating ramman spectra in esp[resso > > i am a new user > > > > > > > b d sahoo > mumbai barc > > > On Tue, Nov 1,

[Pw_forum] Issue with phonon calculation on supercell.

Dear ?ric Germaneau Please follow the recent link of "problem in vc-relax", there is something same problem (If i understood correctly), Prof. Paolo Giannozzi suggested that, this is Gfortran problem. Thanks Sanjeev 2011/10/7 ?ric Germaneau > Dear all, > > Can someone tell me the meaning

[Pw_forum] QHA

Dear Sahoo Plz visit the forum, recent some posts are useful. http://www.democritos.it/pipermail/pw_forum/2011-July/021372.html many more suggestion from Prof. Eyvaz Isaev. wishes sanjeev On Tue, Aug 16, 2011 at 1:38 PM, bhabya sahoo wrote: > compilation problem in QHA code error looks below

[Pw_forum] can pwscf compute elastic constant?

i do not understand, why u asked same question, while your answer was given in old post. Please see and dont make separate. Best Sanjeev On Tue, Jul 5, 2011 at 11:17 AM, bamidele ibrahim wrote: > Dear All, > I want to know if the pwscf code can compute the elastic constant. If > this is

[Pw_forum] phonon partial density

Please first provide your affiliation. The answer for your question is QHA, which is implemented in espresso. Read the manual, and see old post, which is very useful. Regrads Sanjeev On Tue, Jul 5, 2011 at 7:42 AM, lucking-pine wrote: > I want to calculate the phonon partial density.But the

[Pw_forum] how to calculate elastic constants

Hello Adetunji Bamidele Ibrahim, for second question, this is very easy. First of all you need to calculate total energy for different volume or lattice constant in one phase (if you are looking phase transition from one structure to another one), also corresponding pressure then use enthalpy

[Pw_forum] Low energy phonon modes

Dear PWSCF user, Greeting I would like to know weather PWSCF can calculate low energy phonon modes (call it acoustic phonons) for semiconductor nanostructure system like Silicon (size nearly 5 nm). If we see Raman spectra then some of low frequency mode in the range of 5- 50 cm-1. These modes are

[Pw_forum] problem on phonon

Dear Sahoo, Without knowing your input file, how one can judge. Please provide your input file. Further, not fully optimization may be one reason. Best SKG Dept. of Phys. Bhavnagar University Gujarat On Sat, May 28, 2011 at 5:38 PM, bhabya sahoo wrote: > sir > i used to calculate the phonon

[Pw_forum] very high pressure in scf

and translate them by > yourself from the abinig to the qe format? I am sure it won't take more that > a few hours of work ...I can assure you that understanding what a code is > doing for you is a rewarding experience ... > > SB > > On May 27, 2011, at 9:11 AM, Sanjeev Gupta wr

[Pw_forum] very high pressure in scf

ree tool converting input file from ab-init to > PWscf format? You can download it from qe-forge. > http://qe-forge.org/frs/?group_id=10 > I've never used it, but you can give it a try to see if you get the same > PWscf input. > > HTH > > GS > > > Il giorno 27/mag/20

[Pw_forum] very high pressure in scf

# 1,1 Top On Fri, May 27, 2011 at 1:16 AM, Stefano de Gironcoli wrote: > I think the two structures are not the same, or some of the parameters > have non equivalent > values. > stefano > > > On 05/26/2011 08:50 PM, Sanjeev Gupt

[Pw_forum] very high pressure in scf

se Suggest More. > > > On 05/26/2011 04:13 PM, Sanjeev Gupta wrote: > > Dear Maxim > > Thank for kind reply. > > My unit cell is as same in ABINIT as in pwscf in Bohr unit. In addition I > am using the spacegroup 166 (R3(bar)M) space group with conventional unit >

[Pw_forum] very high pressure in scf

Dear Maxim Thank for kind reply. My unit cell is as same in ABINIT as in pwscf in Bohr unit. In addition I am using the spacegroup 166 (R3(bar)M) space group with conventional unit cell rather than primitive unit cell the lattice parameter is taken as below 1. for abinit a=5.359168252 Bohr

[Pw_forum] installing QE

Dear Vicky Go in download package manager and just "type" there "mpich" , it will find the required files, which you install. It is very easy now. Thanks to developer for hard effort to make it easy. After installation of mpich, then you configure as you said before in mail. it will work fine.

[Pw_forum] Yb pseudo

he wavefunction chosen for local potential %% stopping ... ~ Please suggest, where I am wrong Thanking You. Best Regards Sanjeev Gupta Dept. of Physics, Bhavnagar University Bhavnagar-Gujarat ~ -

[Pw_forum] How to restart ph.x calculation?

it works fine. best regards sanjeev On Sun, Apr 10, 2011 at 9:31 PM, Eyvaz Isaev wrote: > Dear Alexandr, > > Use start_q and last_q keywords in ph.in file. start_q is the point for > which calculations were interrupted. last_q - a point to be calculated. > > There are also start_irr and