Re: [QE-users] QE6.8 installation failure on Mac Big Sur
In fact, I had to change both config.guess and config.sub
cp install/config.guess external/devxlib/config/config.guess
cp install/config.sub external/devxlib/config/config.sub
That was for version 7.0. Please, update it for version 7.1
Cheers
Eduardo Menendez Proupin
--
I assume that you know enough never to evaluate a polynomial this way:
p=c(0)+c(1)*x+c(2)*x**2+c(3)*x**3+c(4)*x**4
NR, Sect. 5.3 Polynomials and Rational Functions
("config.guess", not "config.sub")
On Wed, Dec 1, 2021 at 2:14 PM Paolo Giannozzi
wrote:
> Replace the "config.sub" in devxlib with a newer one, or with the one in
> the install/ subdirectory of QE
>
> Paolo
>
> On Tue, Nov 30, 2021 at 11:29 PM Yifan Zhou via users <
> users@lists.quantum-espresso.org> wrote:
>
>> Dear all,
>>
>> I was trying to install QE6.8 to my Mac computer, with M1 processors. It
>> showed me following error when I use "make pw" command":
>>
>> checking build system type... Invalid configuration
>> `aarch64-apple-darwin20.6.0': machine `aarch64-apple' not recognized
>>
>> configure: error: /bin/sh ./config/config.sub aarch64-apple-darwin20.6.0
>> failed
>>
>> if test -d src/ ; then \
>>
>> ( cd src/ ; make ) ; fi
>>
>> make[3]: *** No rule to make target `device_auxfunc_mod.o', needed by
>> `deviceXlib_mod.o'. Stop.
>>
>> make[2]: *** [libsrc] Error 2
>>
>> make[1]: *** [libcuda_devxlib] Error 2
>>
>> make: *** [libcuda] Error 2
>>
>>
>> If you have any advice on this please let me know, I really appreciate it.
>>
>>
>> Thanks in advance.
>>
>>
>> Yifan Zhou, Student @ University of California, San Diego
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Re: [QE-users] Doubt regarding the phonon calculations of RbPbI3
Hi Anupriya,
If decreasing the convergence threshold does not solve or modify
significantly the imaginary frequencies, the problem may be due to the fact
that atoms are in high symmetry positions. See that
ATOMIC_POSITIONS {crystal}
Rb 0.25000 0.584491575 0.824889298
Rb 0.25000 0.084378763 0.675213228
...
the a-coordinates are clearly of high symmetry. The b- and c-coordinates
are not, apparently, but may be due to celldm(2)=2.185 anf celldm(3)=3.657
Perovskites often suffer distortions with respect to the ideal positions,
and the negative (imaginary) frequencies may reflect an incomplete
relaxation.
I suggest shaking the structure a bit, either applying random displacements
to the coordinates, or running a short molecular dynamics. Afterwards,
relax the system using the option nosym=.true.
Variable cell relaxation may also help. In principle, a stressed crystal
should also have phonons with real frequencies, but the stress could induce
a phase transition to a structure with a larger unit cell.
Good luck!
Eduardo Menendez Proupin
--
>
>
> -- Forwarded message --
> From: Anupriya Nyayban
> To: users@lists.quantum-espresso.org
> Cc:
> Bcc:
> Date: Wed, 22 Sep 2021 19:13:27 +0530
> Subject: [QE-users] Doubt regarding the phonon calculations of RbPbI3
> I have calculated the phonon dispersion of orthorhombic RbPbI3 (Pnma)
> using "PHONON" as implemented in Quantum Espresso and found the negative
> frequencies ( which should not be present as suggested in
> https://doi.org/10.1063/1.5131575). It would be great help if you suggest
> to me where I am doing wrong!!! I have provided the computational details
> below:
> 1) The structure first is being relaxed and then the convergence tests are
> performed for Ecut, Kmesh and Lattice parameters.
> 2) Using the relaxed structure with converged parameters, SCF is performed
> with cov_thr=1.0d-8 (ecutwfc=70, ecutrho=600, kmesh=12*6*3); phonon
> calculation is performed with tr2_ph=1.0d-14 at Gamma point, frequencies
> are obtained by imposing acoustic sum rule at the Gamma point with
> asr=simple.
>
> Thank you!!
>
>
> --
> With regards
> Anupriya Nyayban
> Ph.D. Scholar
> Department of Physics
> NIT Silchar
>
>
>
>
>
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Re: [QE-users] Forces are oscillating for P
Bhamu, Set the input parameters trust_radius_min and trust_radius_ini to values smaller than default. If this does not solve the problem, increase ecutrho. Eduardo Menendez Proupin -- I assume that you know enough never to evaluate a polynomial this way: p=c(0)+c(1)*x+c(2)*x**2+c(3)*x**3+c(4)*x**4 NR, Sect. 5.3 Polynomials and Rational Functions El mié, 4 ago 2021 a las 6:01, escribió: > S > -- Forwarded message -- > From: "Dr. K. C. Bhamu" > To: Quantum Espresso users Forum > Cc: > Bcc: > Date: Tue, 3 Aug 2021 16:42:52 +0530 > Subject: [QE-users] Forces are oscillating for P > Dear QE Users, > I am trying to run phosphorus with QE_6.4 but the forces are > oscillating between two values as shown below: > scf.in.out: Total force = 0.008737 Total SCF correction = > 0.02 > scf.in.out: Total force = 0.014135 Total SCF correction = > 0.02 > scf.in.out: Total force = 0.008737 Total SCF correction = > 0.02 > scf.in.out: Total force = 0.014135 Total SCF correction = > 0.02 > > Could you please advise me on how can I handle this? > Below is my input file. > > &CONTROL > calculation = 'vc-relax' >etot_conv_thr = 0.0001 >forc_conv_thr = 0.001 > outdir = './tmp' > prefix = 'pwscf' > pseudo_dir = './PPs' > tprnfor = .true. > tstress = .true. > / > &SYSTEM > degauss = 1.4699723600d-02 > ecutrho = 4.50d+02 > ecutwfc = 4.50d+01 > ibrav = 0 > nat = 24 > nosym = .false. > ntyp = 1 > occupations = 'smearing' > smearing = 'cold' > > / > &ELECTRONS > conv_thr = 1.00d-010 > electron_maxstep = 100 > mixing_beta = 3.00d-01 > / > &IONS > ion_dynamics = 'bfgs' > / > &CELL > / > ATOMIC_SPECIES > P 30.973800d0 P.pbe-n-rrkjus_psl.1.0.0.UPF > ATOMIC_POSITIONS crystal > P0.072058 0.002225 0.186819 > P0.927942 0.997775 0.813181 > P0.850467 0.952993 0.312077 > P0.149533 0.047007 0.687923 > P0.006843 0.134953 0.309157 > P0.993157 0.865047 0.690843 > P0.221928 0.011505 0.366927 > P0.778072 0.988495 0.633073 > P0.763585 0.368292 0.057523 > P0.236415 0.631708 0.942477 > P0.592584 0.186137 0.034895 > P0.407416 0.813863 0.965105 > P0.513831 0.305591 0.165930 > P0.486169 0.694409 0.834070 > P0.396884 0.320114 0.985814 > P0.603116 0.679886 0.014186 > P0.296883 0.682883 0.463448 > P0.703117 0.317117 0.536552 > P0.947588 0.627152 0.367824 > P0.052412 0.372848 0.632176 > P0.201284 0.515294 0.359954 > P0.798716 0.484706 0.640046 > P0.236519 0.676026 0.277493 > P0.763481 0.323974 0.722507 > K_POINTS automatic > 6 3 3 0 0 0 > CELL_PARAMETERS angstrom > 6.024789 0.00 0.00 > -2.0978219998 11.6760139950 0.00 > -1.8239009989 -1.2036659990 11.818676 > > > Regards > Bhamu > > > > > ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[QE-users] restart with larger nqx1, nqx2,nqx3
Hi, Some expensive calculations with hybrid functionals like HSE, can be accelerated using downsampling, i.e., setting nqx1, nqx2,nqx3 to be divisors of the kpoints grid dimensions, at the cost of decreasing quality. In some cases, I would like to split the calculation by means of subsequent calculations with increasing nqx1, nqx2,nqx3. For large nqx1, nqx2,nqx3, I would like to start the calculation from the wavefunctions obtained with smaller nqx1, nqx2,nqx3 (startingwfc ='file') However, PWSCF always begins doing a GGA calculation, then it goes to hybrid, writting a message "EXX: now go back to refine exchange calculation". However, in this process, one loses the wfn read from file. Is it possible to disable the initial GGA calculation with some keyword? Can it be added to a wish list ? Best regards, Eduardo Menendez Proupin -- I assume that you know enough never to evaluate a polynomial this way: p=c(0)+c(1)*x+c(2)*x**2+c(3)*x**3+c(4)*x**4 NR, Sect. 5.3 Polynomials and Rational Functions ___ users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] how to obtain random initial velocities with CP
Thank you Riccardo. I followed the link you pointed and I see the issue is fixed, but I do not know how to download the fixed source file(s). I have more doubts. 1) I have twice tested the procedure of doing 2 CG steps, then restart the CP simulation. In both cases I have gotten an increased electron kinetic energy, significantly larger than before the CG steps. 2) I have succeded to give initial velocities via random initial positions, followed by velocity rescaling, but I stil do not get equilibrium. I find an intriguing statement about the mean square displacements Partial temperatures (for each ionic specie) Species Temp (K) Mean Square Displacement (a.u.) 1 5.54E+02 1.9353E+03 2 3.12E+02 1.9354E+03 3 2.52E+01 1.9352E+03 4 5.43E+02 1.9354E+03 5 1.03E+02 1.9355E+03 3) finally, regarding the documentation statement: 'ATOMIC_VELOCITIES' BEWARE: works only if restart_mode='from_scratch', tested only with electrons_dynamics='cg' I guess one cannot use 'sd' or 'cp', unless it admits restart_mode='restart', otherwise the wfc would be random. Am I missing something? Best regards, Eduardo Menendez Proupin -- Forwarded message -- From: Riccardo Bertossa To: users@lists.quantum-espresso.org Cc: Bcc: Date: Tue, 23 Oct 2018 10:53:28 +0200 Subject: Re: [QE-users] how to obtain random initial velocities with CP Hi, I had too the issue with starting random velocities. I think I've fixed it in the merge request https://gitlab.com/QEF/q-e/merge_requests/189, can you please give it a try? Regarding the reading of the velocities from the input: the documentation was wrong, because the units of the velocities were not correctly stated, it was corrected few months ago. I think that it works also without CG. But please note that after manually setting the velocities you should do a step of CG, that in fact does two steps in this case (one with the starting ions position and one with the position updated with the new velocities), to set the initial wavefunction velocity to a reasonable value with respect to the ions velocities. In my experience, if you don't do this, the kinetic energy that the wfc gain at the end is bigger than the kinetic energy that you get with the electron velocities calculated in the "correct" way. Note also that in the new version, I added an option "change_step" also for the electron_velocities when you change step. This was a little modification to allow a smoother change (before the electron velocities was not updated if the timestep changed, increasing the kinetic energy of the electrons that were no more moving, in some sense, following the ions). electron_velocities CHARACTER 'zero' : restart setting electronic velocities to zero 'default' : restart using electronic velocities of the previous run 'change_step' : restart simulation using electronic velocities of the previous run, with rescaling due to the timestep change. specify the old step via tolp as in tolp = 'old_time_step_value' in au. Note that you may want to specify ion_velocities = 'change_step' Note also that the change of dt is correctly implemented in the autopilot module (so, it is not necessary to use a restart file, and you can change easily dt on the fly and try more values of it) Best regards Riccardo Bertossa ___ users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Consequence of incorrect setup of electron configuration.
Dear Evgeny, 1. Let's consider a supercell with odd number of electron with nspin=1 (non-polarized calculation). The result should probably be incorrect, but how would the error manifest? I'm specifically interested in errors for electron state structure and total energy. A/ The calculation may be good if the system is not magnetic. There are some other important parameters: k-points and smearing. If you have a nk1 x nk2 x nk3 k-point mesh, the calculation if equivalent to a calculation of the supercell of size nk1 x nk2 xnk3 with only the gamma point. Hence, if the number of k-points is even, you have an equivalent even number of electrons. Even if you choose an odd k-points grid, the smearing may cause the HOMO to be half occupied. This is the case for a simple non-magnetic metal, e.g. Al, Cu, where you need a dense k-points grid, and there wide conduction band, and the lowest half of the conduction band gets occupied. In my experience, the incorrect solutions appear when the Fermi level intersects a narrow, non-dispersive conduction band, or have an isolated HOMO level half-occupied. In these cases, applying nspin=2, and breaking the symmetry with starting_magnetization, the half-occupied level or band can split into an occupied and an empty band. This the case of defects in a big supercell (usually gamma point), or the case of a dissociating H2 molecule. The same happens for some crystals where the Fermi level is within a narrow d-band, nspin=1 gives a metallic system, and nspin=2 gives an insulating state. Well, if d-levels are involved the system may still be incorrectly metallic due to the self-interaction error, see the LDA+U method. In case of doubt, and I would say, always, do a test spin-polarized calculation and see if you get a smaller total energy. 2. Let's consider a supercell A which is a half of supercell B. A calculation with supercell B reveals a band with electron population of 1 electron /per B (the system is paramagnetic and the calculation uses nspin=2). Would a band with close energy manifest for a run with supercell A ? A/ If supercell B is the double of A, then you have an even number of electrons, unless you charge the system. I think that you cannot have such band with just one electron in supercell B, assuming the supercell B is not relaxed after duplication of A. Also, note that to make A and B equivalent, for supercell A you need to duplicate the number of k-points, therefore you end with the same number of occupied energy levels and the same energies, just distributed in a different fashion. Best regards Eduardo Menendez www.gnm.cl/emenendez ___ users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[QE-users] how to obtain random initial velocities with CP
Hi, I am unable to start a MD with CP with random velocities setting an initial temperature, using QE 6.3. Reading the input description I understood that I could start it using ion_velocities = 'random', tempw= starting T. However, I always start with 0 temperature. This is my output &CONTROL calculation = 'cp' , restart_mode = 'restart' , pseudo_dir = './' , outdir='./tmp', wfcdir='./tmp', prefix='mapi', nstep = 500, dt = 4.13413733424, ndr = 51, ndw = 51, iprint =50, isave = 50, / &SYSTEM ibrav=0, celldm(1)=1.889726132885 , nat=768, ntyp=5, ecutwfc=35.0 ! 50, ecutrho=200.0 , ! 180, input_dft = 'pbesol', nr1b=21, nr2b=21, nr3b=21, ! nr1b=(2*r_cut)/(Lx)*nr1 nbnd = 1700, / &ELECTRONS conv_thr = 1.0e-5, ! options for CP emass = 400.d0, ! default, Mosconi et al,PCCP 16,16137 (2014), doi: 10.1039/C4CP00569D emass_cutoff = 2.5d0, ! default electron_dynamics = 'verlet' , / &IONS ion_dynamics = 'verlet' , ! 'verlet' , ! ion_temperature = 'not_controlled', ion_velocities = 'random', tempw = 600.0 , / &CELL cell_dynamics = 'none' / In the output I read Ionic position will be re-read from restart file All atoms are allowed to move Ionic temperature control via canonical velocities rescaling : temperature required = 600.0K, tolerance = 100.0K .. nfi ekinc temph tempp etot enthal econsecont vnhh xnhh0 vnhpxnhp0 50.021295550680.00.00 -12738.991035174058 -12738.991035174058 -12738.991033373713 -12738.991031244159 0. 0. 0. 0. 60.057131825070.00.00 -12738.991057915813 -12738.991057915813 -12738.991042309621 -12738.991036596439 0. 0. 0. 0. nfi begins at 5 because there were 4 previous steepest descent dynamics (ould I reset the nfi counter? ), which got the wfc from a PWSCF self-consistent run. Thanks, Eduardo Menendez Proupin University of Chile www.gnm.cl/emenendez ___ users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[QE-users] how to set the electron thermostat fnosee in CP molecular dynamics
Hi fellows, I am exploring the Car Parrinello dynamics for a system with hydrogens: CH3NH3PbI3. With N-H vibrations faster than 3000 cm^-1 and a fluctuating bandgap that may be as small as 1.5 eV , I guess I will need to use a thermostat for the electrons, in order not to use a very small emass and dt. Estimating a minimum electronic frequency sqrt(2Eg/emass), using the default emass=400, I get omega_min~0.016 atomic units. For the N-H vibrations, the frequency is 3000 cm^ -1~ 0.014 atomic units . I read elsewhere than a good frequency for the electron thermostat is 2-3 times the maximum phonon frequency (90THz), this led me to the value fnosee=270.0 My guess is 270 times larger than the default value fnosep=1.D0. Running in a parameter space different to what is tested is generally not a good idea. Am I missing something ? A related, but independent question is about the ion thermostat. The vibrational frequencies of this system are very well separated: ~3000 cm^-1 for N-H and C-H, 900-1200cm^-1 for CH3NH3 molecular vibrations, and <300 cm^-1 for others. Hence, should I set an intermediate fnosep=30.0 (1000 cm^-1), or should I set a Nose-Hoover chain with frequencies close to every phonon band, e.g., fnosep=90.0 30.0 10.0 3.0 Thanks a lot, Eduardo Menendez Proupin University of Chile www.gnm.cl/emenendez ___ users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[Pw_forum] how to set the initial magnetization in non-collinear calculations
Hi, In non-collinear calcularions the direction of the starting magnetic moment of on species is set using angle1(i) and angle(2). How is magnitude of the magnetic moment set? Is it with starting_magnetization(i) ? I just want to be sure. The help just explain the collinear case. angle1(i), i=1,ntyp REAL The angle expressed in degrees between the initial magnetization and the z-axis. For noncollinear calculations only; index i runs over the atom types. angle2(i), i=1,ntyp REAL The angle expressed in degrees between the projection of the initial magnetization on x-y plane and the x-axis. For noncollinear calculations only. Eduardo Menendez Proupin University of Chile ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Shall we calculate some of the parameters by USPP and some other properties by norm conserving PP for same compound?
Dear Sudha, One expects that all the pseudopotentials lead to the same electronic structure that an all-electron calculation. Small numerical differences are expected. This page is useful https://molmod.ugent.be/deltacodesdft for better understanding You should test that the density of states or the bands, are "the same" computed with both sets of peudopotentials. There will be small numerical differences. You should also check the lattice parameteres. Variations smaller than 1% (using the same xc functional) are reasonable. To compute optical properties with the NC you may use the relaxed structure obtained either with USPP or with NC. Small numerical differences are also expected and are acceptable. Care is needed if the differences become qualitative. If you use the USPP structure, with NC the same strusctire is stressed, and the stress and cause splitting of some levels and some peaks in the optical properties. Best regards Eduardo - Mensaje reenviado -- From: Sudha Priyanka To: PWSCF Forum Cc: Bcc: Date: Fri, 12 Jan 2018 04:25:20 -0800 Subject: [Pw_forum] Shall we calculate some of the parameters by USPP and some other properties by norm conserving PP for same compound? Dear Experts, I did scf and other calculation by using USPP, but in epsilon calculation (optical properties) I have no option but have to use only norm conserving PP, Is this correct? Will it make any difference? Shall I compare the calculated properties and parameters by using these different pseudopotentials? For example, If I have calculated electronic properties by USPP and optical properties by norm conserving PP, can I do interpretation of these properties for the same compound? With warm regards Sudha Priyanka G Assistant Professor, Lady Doak College, Madurai, Tamilnadu, India. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] If one atom is heavy, another is lighter, what type of pseudo potentials should be used ?
Dear Sitangshu, Could you, please, expand your answer? I used to think that the spin-orbit coupled pseudopotential is no needed for the light atom. I just think that the spin components are in the wave function as long as one set noncollinear=.true. , or, alternatively, that the coupling terms in the psp of light atoms should be very small. Is there any article explaing the theory of spin-orbit coupled pseudopotential calculations and/or pseudopotential generation? Best regards, Eduardo Menendez Proupin University of Chile -- Mensaje reenviado -- From: Sitangshu Bhattacharya To: PWSCF Forum Cc: Bcc: Date: Sat, 6 Jan 2018 22:47:40 +0530 Subject: Re: [Pw_forum] If one atom is heavy, another is lighter, what type of pseudo potentials should be used ? Dear Jagadish, It depends what you are trying to achieve. For example, spins are required for all elements if your target is to compute optical processes... etc. Regards Sitangshu ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] integrated real space q too different from target q
Hi, I am doing a slab calculation with tqr=.true., and I got this message in the output of PWSCF Message from routine real_space_q: integrated real space q too different from target q 1 1 1 0 0 1 0.24297765 0.24295980 1 1 2 0 0 2 0.21802390 0.21800371 1 2 2 0 0 3 0.17542597 0.17540267 ... Should I worry about it? I don not find significant differences in the total energy and the forces seting tqr=.false. , but also not on CPU time. Thank you Eduardo Menendez Proupin ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] error in compilation of WEST
Thank you Paolo and Jose. The advise from Marco Govoni is to use QE version 6.1. I was able to compile WEST within QE 6.1. Eduardo Menendez Proupin ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] error in compilation of WEST
Hi, I have got an error compiling WEST within qe-6.2.1 May be this be caused by using a two years-old compiler (Intel2015), or due to use -D__DFTI instead of -D_FFTW3 ? exx_go.f90(21): error #7002: Error in opening the compiled module file. Check INCLUDE paths. [PARALLEL_INCLUDE] ... and a lot of subsequent errors. I had no problem making pwall, cp, gwl Thank you , Eduardo Menendez Proupin ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] How to create Vacuum
I think the answer to how to create vacuum is in the example ESM_example. Let me present a related question. How much can we reduce the width of vacuum in the unit cell when using esm_bc='bc1'? Eduardo Menendez Proupin ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Atomic positions of atoms in hybrid perovskite
Dear Kumar, Your input looks formally correct. I guess you have too many k-points. If you can visualize it with xcrysden and if you can run through pwscf, there is no doubt that it is correct. Asking for the coordinates is not a proper question for this forum. However, you can find them here https://github.com/WMD-group/hybrid-perovskites Read the articles there. Also, see https://github.com/cippo1987/Hybrid-perovskites Eduardo Menendez Proupin Universidad de Chile From: Saurabh Kumar To: pw_forum@pwscf.org Cc: Bcc: Date: Wed, 1 Mar 2017 14:35:37 +0530 Subject: [Pw_forum] Atomic positions of atoms in hybrid perovskite CH3NH3PbI3 ? Dear All, I am trying to calculate band structure of hybrid perovskite CH3NH3PbI3. please suggest me the atomic position of atoms in hybrid perovskite CH3NH3PbI3. I make a file for hybrid perovskite CH3NH3PbI3. &CONTROL calculation = 'scf' , outdir = 'CH3NH3PbCl3' , pseudo_dir = '.' , prefix = 'calc' , verbosity = 'low' , ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] carrier lifetime, diffusion length, mobility (HASSAN AHMOUM)
Dear all, The mentioned equations are just for for ZnO, and they use some experimental values of the conductivity. However, the method can be replicated for other II-VI or III-V compounds. I would not dare to replicate it for a different class of material. Computing directly the carrier lifetime is mainly a matter of eletron-phonon interactions and electron-defect interaction, and electron-hole recombination. All of them could be done with the help of Quantum ESPRESSO, using auxiliary codes, but I do not know any implementation to do it. I hope someone hast and cat share it. Eduardo Menendez-Proupin -- Mensaje reenviado -- From: HASSAN AHMOUM To: pw_forum@pwscf.org Cc: Date: Wed, 15 Feb 2017 16:10:10 +0100 Subject: Re: [Pw_forum] carrier lifetime, diffusion length, mobility Dear Abdullah Yes you can calculate indirectly all this parameter's by using Boltztrap code. Boltztrap give you as output file ( carrier concentration, conductivity/carrier lifetime) so by using this equation [1] you can calculate carrier lifetime [1]:K.P.Ong, D.J.Singh, P.Wu, Phys. Rev. B 83 (2011) 115110. carrier lifetime=2.53*(10^-5)*(T^-1)*(n^(-1/3)) [1] were T:temperatur, n: carrier concentration. and if u want calculate mobility use this equation : mobility=conductivity/(charge elementaire*carrier concentration) i think if you have this parameters you can calculate diffusion length. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] ERROR dexx is negative
Hi Thank you Paolo for your answer. If the code is not ready for spin-orbit calculation, let me know, or please, someone let me know. For collinear calculation I had no problem. I also got the code working for spin-orbit and using nqx1=nqx2=nqx3=1. I have found the error with the versions v.6.0 (svn rev. 13079), and v.5.4.0, the ones that I have tried. The error arises after the first step of refining the calculation for EXX, i.e., 1) The codes makes a non-hybrid calculation. 2) There is a message message EXX: now go back to refine exchange calculation, 3) then there is a self-consistent calculation 4) the code prints energies for each k-point and the Fermi energy, 5) then comes the error message the end is like the following : the Fermi energy is 4.0251 ev !total energy = -1494.8872 Ry Harris-Foulkes estimate = -1528.64317856 Ry estimated scf accuracy< 0.0023 Ry convergence has been achieved in 6 iterations %% Error in routine electrons (1): dexx is negative! Check that exxdiv_treatment is appropriate for the system %% stopping ... the same message many times, I guess one for every MPI process. The error also happens using the default ecutrho=4*ecutwfc. -- Mensaje reenviado -- From: Paolo Giannozzi To: PWSCF Forum Cc: Date: Fri, 28 Oct 2016 07:50:53 +0200 Subject: Re: [Pw_forum] ERROR dexx is negative Hi Eduardo Error in routine electrons (1): > dexx is negative! Check that exxdiv_treatment is appropriate for > the system > does this happen at the beginning of the calculation, or towards the end? which code version are you using? ecutwfc = 70.0 ,! same error if use 80.0 > ecutrho = 180.0 , ! also fails if commented out > not good: ecutrho should be 4*70=280. You may however play with the following parameter to speed up the calculation: > ecutfock =180.0, ! also fails if commented out > I am not 100% sure that the code works with spin-orbit and hybrid functionals, though: > lspinorb=.true., > noncolin=.true., > Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] ERROR dexx is negative
Hi, I get this error when trying to perform a noncollinear hybrid functinal calculation, and I get the error %%% Error in routine electrons (1): dexx is negative! Check that exxdiv_treatment is appropriate for the system Below is a summary of the input, there are some comments on variations tha also give the same error. Notably, if nqx1,2,3=1 I get no error. &CONTROL calculation = 'scf' , outdir = './tmp', pseudo_dir = '/home/emenendez/PseudosPW' prefix = 'mapi' , tstress = .false., tprnfor = .true. , wf_collect=.true. / &SYSTEM ibrav = 0, ! celldm(1) = 1.889726 nat = 24, ntyp = 5, ecutwfc = 70.0 ,! same error if use 80.0 ecutrho = 180.0 , ! also fails if commented out ecutfock =180.0, ! also fails if commented out occupations = 'smearing' , degauss = 0.01 , smearing = 'gaussian' , input_dft = 'hse', nqx1=3,nqx2=3,nqx3=3, ! no dexx error if nqx's=1 exxdiv_treatment = 'vcut_ws', x_gamma_extrapolation=.false., ecutvcut = 0.7, lspinorb=.true., noncolin=.true., / &ELECTRONS electron_maxstep = 90, conv_thr = 1.0D-6 , adaptive_thr = .true. , ! same error if .false. startingpot = 'atomic' , startingwfc = 'random' , mixing_mode = 'plain' , mixing_beta = 0.7D0, diagonalization = 'david' , / ATOMIC_SPECIES C 12.011 C_ONCV_PBE-1.0.upf N 14.0067N_ONCV_PBE-1.0.upf H 1.0079 H_ONCV_PBE-1.0.upf Pb 207.2 Pb_ONCV_PBE-1.0_r.oncvpsp.upf I 126.9045 I_ONCV_PBE-1.1_r.oncvpsp.upf CELL_PARAMETERS (angstrom) 8.715251232 -0.117166372 0.009537918 4.176749004 7.610265512 0.021528301 -4.197014982 -2.449751262 7.253510960 ATOMIC_POSITIONS (crystal) C0.054060349 0.579361243 0.784068065 . K_POINTS automatic 3 3 3 0 0 0 So, what can I do? Thanks, Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] FFTXlib compilation error (Azadi, Sam)
Hi Sam, I think the problem is that the path for fftw3.f is not properly included. I have never seen an include line separating the directories by colons. The line IFLAGS = -I../include -I/apps/mpt/mpt-2.13/include:/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/ipp/include:/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/mkl/include:/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/tbb/include:/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/daal/include -I:/apps/intel/2016/mkl/include:/apps/fftw/3.2.2/include should be something like IFLAGS = -I../include -I/apps/mpt/mpt-2.13/include -I/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/ipp/include -I/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/mkl/include -I/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/tbb/include -I/apps/intel/2016/compilers_and_libraries_2016.0.109/linux/daal/include -I/apps/intel/2016/mkl/include -I/apps/fftw/3.2.2/include Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez I'm trying to compile Espresso-5.4.0 on same machines where previous versions were complied and have been running, but getting this error: - fft_scalar.FFTW3.f90(40): #error: can't find include file: fftw3.f ../make.sys:9: recipe for target 'fft_scalar.o' failed although "fftw3.f" path is included in make.sys file which is attached. I appreciate your comments. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] repeated k-points in a phonon calculation
Dear fellows, I would like to know if it is normal to have reapeated k-points in a phonon calculation with PHONON code, or if it other wise a problem with my compilation. I see duplicated k-points in the list, and I also see many points with zero weight. For example, points 1 and 28 are the same, one with weight, and the other with 0 weigh. point 2 is repeated at 53, etc. The k-points grid was defined as automatic 3 3 3 1 1 1 Calculation of q =0.333 0.333 -0.333 .. number of k points=54 Methfessel-Paxton smearing, width (Ry)= 0.0073 cart. coord. in units 2pi/alat k(1) = ( 0.167 0.167 0.167), wk = 0.0740741 k(2) = ( 0.500 0.500 -0.167), wk = 0.000 k(3) = ( 0.167 0.167 -0.500), wk = 0.0740741 k(4) = ( 0.500 0.500 -0.833), wk = 0.000 k(5) = ( 0.167 -0.500 -0.500), wk = 0.0740741 k(6) = ( 0.500 -0.167 -0.833), wk = 0.000 k(7) = ( -0.500 -0.500 -0.500), wk = 0.0740741 k(8) = ( -0.167 -0.167 -0.833), wk = 0.000 k(9) = ( -0.167 0.167 0.167), wk = 0.0740741 k( 10) = ( 0.167 0.500 -0.167), wk = 0.000 k( 11) = ( -0.167 0.167 -0.167), wk = 0.0740741 k( 12) = ( 0.167 0.500 -0.500), wk = 0.000 k( 13) = ( 0.167 -0.167 -0.167), wk = 0.0740741 k( 14) = ( 0.500 0.167 -0.500), wk = 0.000 k( 15) = ( 0.167 0.167 -0.167), wk = 0.0740741 k( 16) = ( 0.500 0.500 -0.500), wk = 0.000 k( 17) = ( -0.167 -0.167 -0.167), wk = 0.0740741 k( 18) = ( 0.167 0.167 -0.500), wk = 0.000 k( 19) = ( 0.167 -0.167 0.167), wk = 0.0740741 k( 20) = ( 0.500 0.167 -0.167), wk = 0.000 k( 21) = ( -0.167 -0.167 0.167), wk = 0.0740741 k( 22) = ( 0.167 0.167 -0.167), wk = 0.000 k( 23) = ( -0.167 0.167 -0.500), wk = 0.0740741 k( 24) = ( 0.167 0.500 -0.833), wk = 0.000 k( 25) = ( 0.167 -0.167 0.500), wk = 0.0740741 k( 26) = ( 0.500 0.167 0.167), wk = 0.000 k( 27) = ( -0.167 -0.167 0.500), wk = 0.0740741 k( 28) = ( 0.167 0.167 0.167), wk = 0.000 k( 29) = ( -0.500 -0.167 0.167), wk = 0.0740741 k( 30) = ( -0.167 0.167 -0.167), wk = 0.000 k( 31) = ( 0.500 -0.167 -0.167), wk = 0.0740741 k( 32) = ( 0.833 0.167 -0.500), wk = 0.000 k( 32) = ( 0.833 0.167 -0.500), wk = 0.000 k( 33) = ( -0.500 0.167 -0.167), wk = 0.0740741 k( 34) = ( -0.167 0.500 -0.500), wk = 0.000 k( 35) = ( 0.500 0.167 0.167), wk = 0.0740741 k( 36) = ( 0.833 0.500 -0.167), wk = 0.000 k( 37) = ( -0.167 -0.500 0.167), wk = 0.0740741 k( 38) = ( 0.167 -0.167 -0.167), wk = 0.000 k( 39) = ( -0.167 0.500 -0.167), wk = 0.0740741 k( 40) = ( 0.167 0.833 -0.500), wk = 0.000 k( 41) = ( 0.167 -0.500 -0.167), wk = 0.0740741 k( 42) = ( 0.500 -0.167 -0.500), wk = 0.000 k( 43) = ( 0.167 0.500 0.167), wk = 0.0740741 k( 44) = ( 0.500 0.833 -0.167), wk = 0.000 k( 45) = ( -0.167 -0.500 -0.500), wk = 0.0740741 k( 46) = ( 0.167 -0.167 -0.833), wk = 0.000 k( 47) = ( -0.500 0.167 0.500), wk = 0.0740741 k( 48) = ( -0.167 0.500 0.167), wk = 0.000 k( 49) = ( 0.500 -0.167 0.500), wk = 0.0740741 k( 50) = ( 0.833 0.167 0.167), wk = 0.000 k( 51) = ( -0.500 0.500 0.167), wk = 0.0740741 k( 52) = ( -0.167 0.833 -0.167), wk = 0.000 k( 53) = ( 0.500 0.500 -0.167), wk = 0.0740741 k( 54) = ( 0.833 0.833 -0.500), wk = 0.000 Thank you Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez
[Pw_forum] why does band calculation takes too long
Hi, I wonder why is the band calculation much longer than a scf calcuation. I did a calculation for a 64-atoms supercell using 20 cpu cores. In summary, I did 1) SCF calculation with only gamma point, run in two minutes. 2) Non-self-consistent band calculation with 27 k-points. In the nscf calculation each k-point takes 15-20 minutes and the total calculation lasts 7 hours. I understand that for the k-points along the line the wfc are complex, the symmetry is smaller, but even so the time scale is quite different. The machine has to keep all the wfc in memory, but it was not swapping. Even the gamma point took 15 minutes, why does it takes longer than the scf calculation? Please, let me know if I am doing something wrong. Below are the inputs for the scf and the bnd calculations. SCF: &CONTROL calculation = 'scf' restart_mode='from_scratch', pseudo_dir = "./", outdir="./tmp/", tstress = .true., tprnfor = .true. , prefix= 'cdte64', disk_io = 'low', etot_conv_thr = 1.0D-3, wf_collect=.TRUE., verbosity='high' / &SYSTEM ibrav= 1, celldm(1) = 25.02, nat = 64, ntyp = 2, ecutwfc = 28.67, ecutrho = 180, degauss = 0.001D0, occupations = "smearing", smearing = "gauss", tot_charge = 0, nspin = 1 , ! set to 2 for spin polarized ! tot_magnetization = 0 , ! change to 1 / &ELECTRONS diagonalization='david' conv_thr = 1.D-6, mixing_beta = 0.4D0, diago_david_ndim= 2, / &IONS pot_extrapolation='second_order', trust_radius_max = 0.7, trust_radius_ini = 0.7, / ATOMIC_SPECIES Cd 112.411 cd_pbe_v1.uspp.F.UPF Te 127.600 te_pbe_v1.uspp.F.UPF ATOMIC_POSITIONS (alat) Cd 0.5000 0.5000 0.5000 Cd 0. 0. 0. Cd 0.2500 0.2500 0. …. K_POINTS gamma The NSCF band calculation input is: &CONTROL calculation = 'bands' ! restart_mode='from_scratch', pseudo_dir = "./", outdir="./tmp/", tstress = .true., tprnfor = .true. , prefix= 'cdte64', disk_io = 'low', etot_conv_thr = 1.0D-3, verbosity='high' / &SYSTEM ibrav= 1, celldm(1) = 25.02, nat = 64, ntyp = 2, ecutwfc = 28.67, ecutrho = 180, degauss = 0.001D0, occupations = "smearing", smearing = "gauss", tot_charge = 0, nspin = 1 , ! set to 2 for spin polarized ! tot_magnetization = 0 , ! change to 1 / &ELECTRONS diagonalization='david' conv_thr = 1.D-6, mixing_beta = 0.4D0, diago_david_ndim= 2, / &IONS pot_extrapolation='second_order', trust_radius_max = 0.7, trust_radius_ini = 0.7, / ATOMIC_SPECIES Cd 112.411 cd_pbe_v1.uspp.F.UPF Te 127.600 te_pbe_v1.uspp.F.UPF ATOMIC_POSITIONS (alat) Cd 0.5000 0.5000 0.5000 Cd 0. 0. 0. Cd 0.2500 0.2500 0. …. K_POINTS crystal_b 3 0.500 0.500 0.500 17 0.000 0.000 0.000 10 0.500 0.000 0.000 1 Thank you. Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] non-cubic dielectric tensor in a cubic crystal.
Thanks for your response Paolo. I did exactly as you said, I used
dynmat.x . I think the asymetry comes from Eq. (2) of Fennie&Rabe due to
having a different frequency, or from eq (3) due to having a different
eigenvector. In fact, when I specify no direction with the vector q(i), I
get three equal frecuencies and equal components for the dielectric tensor.
Looking at the eigenvectors, I think the asymetry comes from Eq. 2. I made
a simple calculation with the following data
# mode [cm-1][THz] IR
1 -0.00 -0.0.
2 0.000.0.
3 0.000.0.
4133.013.98752.3657
5133.013.98752.3657
6154.234.62382.3657
Electronic dielectric permittivity tensor (F/m units)
11.3878180.00 -0.00
0.00 11.387818 -0.00
0.000.00 11.387818
... with zone-center polar mode contributions
14.3065430.000.00
0.00 15.312431 -0.00
0.00 -0.00 15.312431
freq (6) = 4.623845 [THz] = 154.234861 [cm-1]
( -0.750355 0.00 0.00 0.00-0.00 0.00 )
( 0.661035 -0.00-0.00 0.00 0.00 -0.00 )
Only the 6th eigenvector has component in axis 1. A very simple
calculation shows that you are right, regarding Eq (2) I just need to
correct the omega_m from 154 to 133 cm^-1
[emenendez@leftraru2 VC-relax]$ echo '11.387818+(15.312431-11.387818)'|bc -l
15.312431
[emenendez@leftraru2 VC-relax]$ echo
'11.387818+(15.312431-11.387818)*(133.01/154.23)^2'|bc -l
14.30677507068329634588
So, is this an error ?
Thank you again
Eduardo
-- Mensaje reenviado --
> From: Paolo Giannozzi
> To: PWSCF Forum
> Cc:
> Date: Mon, 11 Jan 2016 21:51:24 +0100
> Subject: Re: [Pw_forum] non-cubic dielectric tensor in a cubic crystal.
> Hi Eduardo
>
> you used dynmat.x, didn't you? the \epsilon_0 tensor is computed is
> subroutine polar_mode_permittivity of PHonon/PH/dynmat.f90. The header
> mentions a nonexistent reference (the correct page number should be 184111):
> ! Algorithm from Fennie and Rabe, Phys. Rev. B 68, 18411 (2003)
> My guess is that the algorithm assumes TO frequencies only, but LO
> frequencies are used instead since you specified a direction for q=>0.
>
> Paolo
>
> On Mon, Jan 11, 2016 at 8:10 PM, Eduardo Menendez
> wrote:
>
>> Hi,
>>
>> I am computing the dielectric funciton of a cubic material (CdTe).
>> I am surprised that the to see a result like this the dielectric tensor
>> below:
>>
>> # mode [cm-1][THz] IR
>> 1 0.000.0.
>> 2 0.000.0.
>> 3 0.000.0.
>> 4133.013.98752.3657
>> 5133.013.98752.3657
>> 6154.234.62382.3657
>>
>> Electronic dielectric permittivity tensor (F/m units)
>> 11.3878180.00 -0.00
>> 0.00 11.387818 -0.00
>> 0.000.00 11.387818
>>
>> ... with zone-center polar mode contributions
>> 14.3065430.00 -0.00 (HERE IS ACKWARD)
>> 0.00 15.312431 -0.00
>> -0.00 -0.00 15.312431
>>
>> I (guess that) undertand the first tensor above as \epsilon_{\infty}, and
>> the second tensor as \epsilon_0. Why is the first component 14.3 different
>> from the others 15.31, shouldn't it be a diagonal tensor ? 15.31 is
>> consistent with epsilon_infty and the Lyddane-Sachs-Teller formula.
>>
>> Well, I set q(1)=1, q(2)=0,q(3)=0, so I guess the component 11 is a
>> longitudinal dielectric constant. I see that changing the vector q also
>> change the tensor However, I think that for an LO phonon the electric
>> displacement is 0, so is null the longitudinal dielectric constant.
>>
>> Sorry, I did never see this in textbooks. Finally, and practically, if
>> 14.3 is a longitudinal dielectric constant, is this the dielectric constant
>> that screens a static constant electric field ?
>>
>> Thank you,
>>
>> Eduardo Menendez Proupin
>> Departamento de Fisica, Facultad de Ciencias, Universidad de Chile
>> URL: http://www.gnm.cl/emenendez
>>
>>
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[Pw_forum] non-cubic dielectric tensor in a cubic crystal.
Hi,
I am computing the dielectric funciton of a cubic material (CdTe).
I am surprised that the to see a result like this the dielectric tensor
below:
# mode [cm-1][THz] IR
1 0.000.0.
2 0.000.0.
3 0.000.0.
4133.013.98752.3657
5133.013.98752.3657
6154.234.62382.3657
Electronic dielectric permittivity tensor (F/m units)
11.3878180.00 -0.00
0.00 11.387818 -0.00
0.000.00 11.387818
... with zone-center polar mode contributions
14.3065430.00 -0.00 (HERE IS ACKWARD)
0.00 15.312431 -0.00
-0.00 -0.00 15.312431
I (guess that) undertand the first tensor above as \epsilon_{\infty}, and
the second tensor as \epsilon_0. Why is the first component 14.3 different
from the others 15.31, shouldn't it be a diagonal tensor ? 15.31 is
consistent with epsilon_infty and the Lyddane-Sachs-Teller formula.
Well, I set q(1)=1, q(2)=0,q(3)=0, so I guess the component 11 is a
longitudinal dielectric constant. I see that changing the vector q also
change the tensor However, I think that for an LO phonon the electric
displacement is 0, so is null the longitudinal dielectric constant.
Sorry, I did never see this in textbooks. Finally, and practically, if
14.3 is a longitudinal dielectric constant, is this the dielectric constant
that screens a static constant electric field ?
Thank you,
Eduardo Menendez Proupin
Departamento de Fisica, Facultad de Ciencias, Universidad de Chile
URL: http://www.gnm.cl/emenendez
“No cometerás actos impuros ni publicarás en revistas open-acces”
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[Pw_forum] a few frequencies in PHONON calculation
Hi everybody, Let me insist with a question I posted two days ago. I interpret from the manual that one can compute a few phonon irreducible representations. If this means that one can compute a few phonon frequencies for a big system that could be useful to do short convergence tests. I guess these frequencies are true for a high symmetry system, but for a low symmetry system I do not know (should I ) how the irreducible representations can be determined before diagonalizing the full dynamical matrix. I have mad a test using last_irr = 10 , and then last_irr = 14, and I get different frequencies. Maybe I do something wrong, or maybe I just do not understand the goal of "last_irr" keyword. I appreciate that someone kindly clarifies this issue. Best regards Eduardo Date: Tue, 22 Dec 2015 14:48:45 -0300 Subject: [Pw_forum] a few frequencies in PHONON calculation Hi, I have one doubt about the PHONON code. Is it possible to compute just a few phonon frequencies using the PHONON keywords last_irr, ldiag ? For example, using last_irr = 10, ldiag=.true.,, may one find the frequencies of just the first irreducible representations ? Thank you, Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez “No cometerás actos impuros ni publicarás en revistas open-acces” ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] a few frequencies in PHONON calculation
Hi, I have one doubt about the PHONON code. Is it possible to compute just a few phonon frequencies using the PHONON keywords last_irr, ldiag ? For example, using last_irr = 10, ldiag=.true.,, may one find the frequencies of just the first irreducible representations ? Thank you, Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Raman and IR spectra
I do not see an obvious impossibility to calculate the IR and Raman spectrum of a cluster made of metal elements. A cluster is not a metal, just treat it like a molecule. A metal is a periodic quasi-infinite crystal with zero gap between occupied and empty levels. If the cluster has an open shell configuration , i.e., the HOMO is partiallly occupied, then it may not be possible to calculate IR and Raman with QE. However, if this were the case, the cluster would probably undergone a distortion (Jahn Teller effect) and will open a gap. Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez “No cometerás actos impuros ni publicarás en revistas open-acces” On 10/27/15, Gul Rahman wrote: > Dear All, > Is it possible to calculate the Raman and IR spectra of metallic clusters > with QE. I heard it is possible to calculate it for semiconductors, but not > for metallic. > Why QE is not able to calculate IR and Raman spectra of a metallic system. > Thanks, > Gul > > > -- > > > Dr. Gul Rahman > Assistant Professor, > Department of Physics, > Quaid-i-Azam University, > Islamabad, Pakistan > http://www.qau.edu.pk/profile.php?id=818020 > - ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] SATA vs SAS
Hi, Thanks for the replies to my question. Some answers were devoted to solid state devices (SSD), but I had asked about SAS (Serial attached SCSI) in comparison to SATA disks. I know that SAS are better for high I/O load. The point is how critical ist that for QE. I have to choice between (better CPU with SATA) vs (worse CPU with SAS). I have the feeling (from the times of IDE hard disks), that under heavy I/O load (using swap memory), the use of CPU drops to 1% and calculations are impractical. I guess it is still true, i.e., heavy I/O are to be avoided in ab initio calculations. Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ?Science may be described as the art of systematic oversimplification.? Karl Popper -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140808/5d696ebb/attachment.html
[Pw_forum] SATA vs SAS
Hi, Is it critical to use SAS disks (compared to SATA) for good performance of Quantum ESPRESSO? Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140806/50a0b389/attachment.html
[Pw_forum] k-points for optical properties
Dear Paolo, Thanks for your response. Yes, tetrahedra should work, but for large unit cells (108 atoms) I have problems because to obtain reasonable results the k-mesh must be somewhat dense and I have a problem where the wfc occupy more terabytes than allowed by the computer systems. I think I can combine a coarse Monkhorst-Pack mesh with a dense mesh, but I have doubts on how to set the weights at the interfaces between the coarse and the dense mesh. I guess I should read on self-adaptative integration algorithms. Doing that, I think I can run epsilon.x with with groups of few k-points and add the dielectric functions obtained for each set. >> Is there any available tool or method to generate non-uniform k-point >> grids (and weights) useful to sample the van-Hove singularities in the >> DOS or the joint DOS for calculations of dielectric function? >not that I know. If however the goal is to obtain correct van Hove >singularities, with tetrahedra you should obtain them. Best regards, Eduardo Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ?Science may be described as the art of systematic oversimplification.? Karl Popper -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140722/b143397f/attachment.html
[Pw_forum] k-points for optical properties
Hi, Is there any available tool or method to generate non-uniform k-point grids (and weights) useful to sample the van-Hove singularities in the DOS or the joint DOS for calculations of dielectric function? Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ?Science may be described as the art of systematic oversimplification.? Karl Popper -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140719/e4f0dbd7/attachment.html
[Pw_forum] QE on Xeon Phi
Thank you Axel. Your advise rises another doubt. Can we get the maximum performance from a highly clocked CPU? I used to consider that the the fastest CPUs were too fast for the memory access, resulting in bottlenecks. Of couse it depends on cache size. >Stick with the cpu. For QE you should be best off with intel. Also you are likely to >get the best price/performance ratio with CPUs that have less than the maximum >number of cpu cores and a higher clock instead. Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ?Science may be described as the art of systematic oversimplification.? Karl Popper -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140714/a7e06ac8/attachment.html
[Pw_forum] QE on Xeon Phi
Dear fellows, I need to know if it is worth to buy Xeon coprocessors for use with Quantum ESPRESSO. I need make a choice between more CPU or less CPU+coprocessor, and even to choose between few Intel cores vs not-so-few AMD Opterons. Searching in the Web I have found these implemntatios of QE on Xeon Phi: (1) a Quantum ESPRESSO modified for Xeon Phi, by Fabio Affinito, and (2) an instructions for instalation of standard Quantum ESPRESSO with some automagic use of Xeon Phi by the MKL. Here is the site https://software.intel.com/en-us/articles/quantum-espresso-for-intel-xeon-phi-coprocessor Is the choice (1) available and mature enough for a general use, or at least for using PWscf for calculations of defects in supercells containg a multiple of 64 atoms? Is choice (2) effcient? I see a benchmark in that site that, if I interpret correctly, it indicates only a 12% improvement. Hence I think this automagic choice is not worth enough. Am I wrong? Choice 2 needs installing MPSS (Manycore Platform Software Stacks) and Intel MPI. Does choice (1) also require these components? MPSS is supported for Red Hat and SUSE. Is there any good experience with Debian or Ubuntu? At this point I feel rather conservative :-( . If not warmed by enthusiastic praise of coprocessors, or GPU, I will keep looking for as many CPU cores as possible. Cheers, Eduardo Menendez Proupin Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://www.gnm.cl/emenendez ?Science may be described as the art of systematic oversimplification.? Karl Popper -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140711/2e8bb69d/attachment.html
