> A famous example is Li which PsP was removed from PWSCF website. I met the > same problem with K and Cs using my own pseudopotentials.
Li PsP is still on the website,http://www.quantum-espresso.org/pseudo/1.3/html/Li.html. Name: Lithium Symbol: Li Atomic number: 3 Atomic configuration: [He] 2s1 Atomic mass: 6.914 (2) Available pseudopotentials: Li.pz-n-vbc.UPF (details) Perdew-Zunger (LDA) exch-corr nonlinear core-correction Von Barth-Car (direct fit) Li.pbe-n-van.UPF (details) Perdew-Burke-Ernzerhof (PBE) exch-corr nonlinear core-correction Vanderbilt ultrasoft Li.pw91-n-van.UPF (details) Perdew-Wang 91 gradient-corrected functional nonlinear core-correction Vanderbilt ultrasoft vega ================================================================================= Vega Lew (weijia liu) PH.D Candidate in Chemical Engineering State Key Laboratory of Materials-oriented Chemical Engineering College of Chemistry and Chemical Engineering Nanjing University of Technology, 210009, Nanjing, Jiangsu, China -------------------------------------------------- From: "Eyvaz Isaev" <eyvaz_is...@yahoo.com> Sent: Sunday, August 31, 2008 4:19 AM To: "vega" <vegalew at hotmail.com> Subject: Re: [Pw_forum] something strange in rutile and anatase calculation > --- On Sat, 8/30/08, vega <vegalew at hotmail.com> wrote: > >> thank you for replying > > Welcome. > >> >> >But as far as I know sometime PsPs (not for Ti, in >> general) fail with phonon calculations. >> >> Do you think there is a certain PsPs that could >calculate the lattice >> parameters and bulk modulus correctly >but only fail with phonon >> calculations. > > >> If you find a certain PsPs fail with phonon calculations >> what will you do next? how to adjust it? >> > In this case you have to generate a new PsP, if you like to deal with > phonons. Otherwise, use what you have and what you prefer. > > Bests, > Eyvaz. > P.S. This is not a problem of the QE code. Several times I heard complains > about PAW potentials for VASP. > >> vega >> >> >> ================================================================================= >> Vega Lew (weijia liu) >> PH.D Candidate in Chemical Engineering >> State Key Laboratory of Materials-oriented Chemical >> Engineering >> College of Chemistry and Chemical Engineering >> Nanjing University of Technology, 210009, Nanjing, Jiangsu, >> China >> >> -------------------------------------------------- >> From: "Eyvaz Isaev" <eyvaz_isaev at yahoo.com> >> Sent: Sunday, August 31, 2008 12:15 AM >> To: "vega" <vegalew at hotmail.com> >> Subject: Re: [Pw_forum] something strange in rutile and >> anatase calculation >> >> > Dear Vega, >> > >> > --- On Sat, 8/30/08, vega <vegalew at hotmail.com> >> wrote: >> > >> >> > I have read the paper and have 2 comments. >> >> >> >> I used to think the paper was written by you. Why >> > did you need to read >> >> it again? >> > >> > As I replied to Willy Kohn's mail, I meant reading >> the paper from >> > Jpn.J.Appl.Phys. Lett., he recommended, but not my own >> paper from PNAS. >> > So, there will be no confusing. All what I said >> concerned only the paper >> > and PsPs used in JpnJApplPhys. >> > >> > If you have done lots of calculations with the Ti >> pseudopotential you used >> > and got reliable results, well, it looks like to be >> transferable. The >> > transferability means that you can put a bare ionic >> atom (with its PsP) >> > into different environment, but its scattering >> properties should be the >> > same as for a real atom. >> > A transferable PsP for a given atom (say Ti) should >> work in most cases (as >> > in your case, if you got results comparable with >> experiments and >> > independent methods). The way you supposed (lattice >> parameters and bulk >> > modulus for known phases and compounds) is correct to >> check a PsP >> > transferability. But as far as I know sometime PsPs >> (not for Ti, in >> > general) fail with phonon calculations. >> > >> > As references you cited support your calculations you >> can belive your own >> > results. >> > >> > Hopefully I replied briefly all questions you posted >> in this mail. >> > >> > Bests, >> > Eyvaz. >> > >> > >> >> > 2. They used only LDA, but not GGA. As it is >> well >> >> known (hopefully I am >> >> > not wrong here) LDA fails for the ground >> state of Fe. >> >> In contrast to this, >> >> > GGA does a good job for Fe. >> >> >> >> But I found the sentence like this, 'The >> generalized >> >> gradient approximation >> >> in the Perdew- >> >> Burke-Ernzerhof parametrization was chosen to >> treat the >> >> exchange-correlation >> >> effects.' in the Methods section. I was rather >> >> confused. >> >> >> >> > So, it will be very good if Vega can >> calculate the >> >> total energies for the >> >> > rutile and anatase phases in odrer to study >> whether >> >> their energy position >> >> > is dependent on the choice of >> exchange-correlation >> >> functional. >> >> >> >> I used to do a little test against this. The >> results >> >> suggested that the GGA >> >> overestimate the lattice parameters a little with >> 1% and >> >> LDA underestimate >> >> the lattice parameters for both case. I didn't >> pay a >> >> lot attentions on >> >> energy position calculated by LDA. I'll check >> it as >> >> soon as possible. But to >> >> my best knowledge, there were many reports >> suggested that >> >> the calculated >> >> anatase stability was better than rutile. For >> example, J. >> >> Chem. Phys. 126, >> >> 154703 (2007) said 'No matter which >> Hamiltonian or >> >> method is used, the >> >> results on relative stability of both phases >> suggest that >> >> the anatase is >> >> more stable than the rutile phase of TiO2.'. >> Same >> >> conclusion also was >> >> mentioned in Phys. Rev. B 2002, 65 (22) and Phys. >> Rev. B >> >> 2007, 76 et al. >> >> >> >> > It might also be that there is a >> transferability >> >> problem for these PsPs (I >> >> > can not prove this, just suggestion). >> >> >> >> Because I'm a beginner for QE. I though >> >> pseudopotentials is quite >> >> transferable and we could use the same >> pseudopotentials for >> >> any mater >> >> containing the same kind of element. For instance, >> we could >> >> use the same >> >> pseudopotentials for hcp Ti, TiN, rutile, >> brookite, anatase >> >> and other >> >> polymorphs under high pressure, such as >> >> Fluorite,Baddeleyite et al. But now, >> >> I think I'm probably wrong. Could you tell me >> the >> >> difference between the Ti >> >> pseudopotentials for hcp-Ti and TiN or many >> polymorphs of >> >> TiO2? And I also >> >> wonder how to judge whether the pseudopotentials >> is >> >> suitable for certain >> >> calculation? to calculate the lattice parameters >> and >> >> compare the results >> >> with the experimental data? Is that enough? >> >> >> >> > It is my pleasure that they also mentioned >> that >> >> including of phonon >> >> > contribution might be important. >> >> I would like to calculate the phonon contribution. >> But I >> >> have few knowledge >> >> about it. I'll learn to do that if necessary. >> >> >> >> vega >> >> >> >> >> >> >> ================================================================================= >> >> Vega Lew (weijia liu) >> >> PH.D Candidate in Chemical Engineering >> >> State Key Laboratory of Materials-oriented >> Chemical >> >> Engineering >> >> College of Chemistry and Chemical Engineering >> >> Nanjing University of Technology, 210009, Nanjing, >> Jiangsu, >> >> China >> >> >> >> -------------------------------------------------- >> >> From: "Eyvaz Isaev" >> <eyvaz_isaev at yahoo.com> >> >> Sent: Saturday, August 30, 2008 7:14 AM >> >> To: "PWSCF Forum" >> <pw_forum at pwscf.org> >> >> Subject: Re: [Pw_forum] something strange in >> rutile and >> >> anatase calculation >> >> >> >> > Dear Wei, >> >> > >> >> > Thanks a lot for bringing the paper to our >> attention. >> >> > >> >> > I have read the paper and have 2 comments. >> >> > >> >> > 1. They used only norm-conserving >> pseudopotentials >> >> constructed by means of >> >> > different methods. >> >> > >> >> > 2. They used only LDA, but not GGA. As it is >> well >> >> known (hopefully I am >> >> > not wrong here) LDA fails for the ground >> state of Fe. >> >> In contrast to this, >> >> > GGA does a good job for Fe. >> >> > >> >> > So, it will be very good if Vega can >> calculate the >> >> total energies for the >> >> > rutile and anatase phases in odrer to study >> whether >> >> their energy position >> >> > is dependent on the choice of >> exchange-correlation >> >> functional. >> >> > >> >> > It might also be that there is a >> transferability >> >> problem for these PsPs (I >> >> > can not prove this, just suggestion). >> >> > >> >> > It is my pleasure that they also mentioned >> that >> >> including of phonon >> >> > contribution might be important. >> >> > >> >> > Bests, >> >> > Eyvaz. >> >> > >> >> > >> >> >> ------------------------------------------------------------------- >> >> > Prof. Eyvaz Isaev, >> >> > Theoretical Physics Department, Moscow State >> Institute >> >> of Steel & Alloys, >> >> > Russia, >> >> > Department of Physics, Chemistry, and Biology >> (IFM), >> >> Linkoping University, >> >> > Sweden >> >> > Condensed Matter Theory Group, Uppsala >> University, >> >> Sweden >> >> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, >> >> eyvaz_isaev at yahoo.com >> >> > >> >> > >> >> > --- On Fri, 8/29/08, willy kohn >> >> <willykohn at gmail.com> wrote: >> >> > >> >> >> From: willy kohn >> <willykohn at gmail.com> >> >> >> Subject: Re: [Pw_forum] something strange >> in >> >> rutile and anatase >> >> >> calculation >> >> >> To: "PWSCF Forum" >> >> <pw_forum at pwscf.org> >> >> >> Date: Friday, August 29, 2008, 10:02 PM >> >> >> Hi, Vega: >> >> >> >> >> >> A recent result (Jpn. J. Appl. Phys. 39 >> (2000) >> >> L847) showed >> >> >> that different >> >> >> pseudopotential leaded to different >> conclusions. >> >> >> >> >> >> Best, >> >> >> >> >> >> Wei >> >> >> >> >> >> On Thu, Aug 28, 2008 at 4:28 AM, vega >> >> >> <vegalew at hotmail.com> wrote: >> >> >> >> >> >> > Dear all, >> >> >> > >> >> >> > It is known that the rutile is more >> stable >> >> than >> >> >> anatase in thermodynamics. >> >> >> > Surprisingly, when I did the >> vc-relax >> >> calculation by >> >> >> QE, I found >> >> >> > the calculated energy of anatase >> lower than >> >> rutile. >> >> >> Both vc-relax >> >> >> > calculation for rutile and anatase >> onverged >> >> in 6 scf >> >> >> cycles and 3 bfgs >> >> >> > steps, giving the final enthalpy = >> >> -362.7585836890 Ry >> >> >> for rutile and >> >> >> > -725.5447425835 Ry for antase. So >> the average >> >> energy >> >> >> of [TiO2] unit >> >> >> > is -181.3792918445 Ry for rutile and >> >> -181.386185645875 >> >> >> Ry for anatase. It >> >> >> > looks like anatase is more stable >> than >> >> rutile. Do you >> >> >> think it was quite >> >> >> > strange? >> >> >> > >> >> >> > To make the calculation both for >> anatase and >> >> rutile >> >> >> comparable, I used the >> >> >> > same ecutwfc=40 Ry and ecutwfc=400 >> Ry, and a >> >> quite >> >> >> dense k-point mesh for >> >> >> > both case, 4x4x7 for rutile and >> 5x5x2 for >> >> anatase. >> >> >> > >> >> >> > for better understanding in my >> calculation, >> >> please >> >> >> read the input file >> >> >> > below, >> >> >> > for anatase case, >> >> >> > &CONTROL >> >> >> > title = >> 'Anatase >> >> >> lattice' , >> >> >> > calculation = >> >> 'vc-relax' , >> >> >> > restart_mode = >> >> 'from_scratch' >> >> >> , >> >> >> > outdir = >> >> >> > >> >> >> >> >> >> '/home/hjfeng/vega/TiO2/Anatase/lattice/vctest/tmp/' >> >> >> , >> >> >> > wfcdir = >> >> '/tmp/' , >> >> >> > pseudo_dir = >> >> >> >> '/home/hjfeng/vega/espresso-4.0/pseudo/' , >> >> >> > prefix = >> 'Anatase >> >> >> lattice' , >> >> >> > disk_io = >> 'none' >> >> , >> >> >> > nstep = 1000 >> , >> >> >> > / >> >> >> > &SYSTEM >> >> >> > ibrav = 6, >> >> >> > celldm(1) = >> 7.1356, >> >> >> > celldm(3) = >> 2.5122, >> >> >> > nat = 12, >> >> >> > ntyp = 2, >> >> >> > ecutwfc = 40 , >> >> >> > ecutrho = 400 , >> >> >> > / >> >> >> > &ELECTRONS >> >> >> > >> >> >> > / >> >> >> > &IONS >> >> >> > ion_dynamics = >> 'bfgs' >> >> , >> >> >> > / >> >> >> > &CELL >> >> >> > cell_dynamics = >> 'bfgs' >> >> , >> >> >> > / >> >> >> > ATOMIC_SPECIES >> >> >> > Ti 47.86700 >> Ti.pw91-sp-van_ak.UPF >> >> >> > O 15.99940 O.pw91-van_ak.UPF >> >> >> > ATOMIC_POSITIONS crystal >> >> >> > Ti 0.000000000 >> 0.000000000 >> >> 0.000000000 >> >> >> > Ti 0.500000000 >> 0.500000000 >> >> 0.500000000 >> >> >> > Ti 0.000000000 >> 0.500000000 >> >> 0.250000000 >> >> >> > Ti 0.500000000 >> 0.000000000 >> >> 0.750000000 >> >> >> > O 0.000000000 >> 0.500000000 >> >> 0.042000000 >> >> >> > O 0.000000000 >> 0.000000000 >> >> 0.208000000 >> >> >> > O 0.500000000 >> 0.500000000 >> >> 0.292000000 >> >> >> > O 0.000000000 >> 0.500000000 >> >> 0.458000000 >> >> >> > O 0.500000000 >> 0.000000000 >> >> 0.542000000 >> >> >> > O 0.500000000 >> 0.500000000 >> >> 0.708000000 >> >> >> > O 0.000000000 >> 0.000000000 >> >> 0.792000000 >> >> >> > O 0.500000000 >> 1.000000000 >> >> 0.958000000 >> >> >> > K_POINTS automatic >> >> >> > 5 5 2 1 1 1 >> >> >> > >> >> >> > for rutile case, >> >> >> > >> >> >> > &CONTROL >> >> >> > title = >> Rutile_lattice >> >> , >> >> >> > calculation = >> >> 'vc-relax' , >> >> >> > restart_mode = >> >> 'from_scratch' >> >> >> , >> >> >> > outdir = >> >> >> > >> >> >> '/home/vega32/TiO2/rutile/lattice/vcrelax/tmp' >> >> >> , >> >> >> > wfcdir = >> >> '/tmp/' , >> >> >> > pseudo_dir = >> >> >> >> '/home/vega32/espresso-4.0.1/pseudo/' , >> >> >> > prefix = >> 'Anatase >> >> >> lattice' , >> >> >> > disk_io = >> 'none' >> >> , >> >> >> > nstep = 1000 >> , >> >> >> > / >> >> >> > &SYSTEM >> >> >> > ibrav = 6, >> >> >> > celldm(1) = >> 8.6814, >> >> >> > celldm(3) = >> 0.6441, >> >> >> > nat = 6, >> >> >> > ntyp = 2, >> >> >> > ecutwfc = 40 , >> >> >> > ecutrho = 400 , >> >> >> > / >> >> >> > &ELECTRONS >> >> >> > >> >> >> > / >> >> >> > &IONS >> >> >> > ion_dynamics = >> 'bfgs' >> >> , >> >> >> > / >> >> >> > &CELL >> >> >> > cell_dynamics = >> 'bfgs' >> >> , >> >> >> > / >> >> >> > ATOMIC_SPECIES >> >> >> > O 15.99940 O.pw91-van_ak.UPF >> >> >> > Ti 47.90000 >> Ti.pw91-sp-van_ak.UPF >> >> >> > ATOMIC_POSITIONS crystal >> >> >> > O 0.304800000 >> 0.304800000 >> >> 0.000000000 >> >> >> > O 0.695200000 >> 0.695200000 >> >> 0.000000000 >> >> >> > O 0.195200000 >> 0.804800000 >> >> 0.500000000 >> >> >> > O 0.804800000 >> 0.195200000 >> >> 0.500000000 >> >> >> > Ti 0.500000000 >> 0.500000000 >> >> 0.500000000 >> >> >> > Ti 0.000000000 >> 0.000000000 >> >> 0.000000000 >> >> >> > K_POINTS automatic >> >> >> > 4 4 7 1 1 1 >> >> >> > >> >> >> > vega >> >> >> > >> >> >> > >> >> >> >> >> >> ============================================================== >> >> >> > Vega Lew ( weijia liu) >> >> >> > PH.D Candidate in Chemical >> Engineering >> >> >> > State Key Laboratory of >> Materials-oriented >> >> Chemical >> >> >> Engineering >> >> >> > College of Chemistry and Chemical >> Engineering >> >> >> > Nanjing University of Technology, >> 210009, >> >> Nanjing, >> >> >> Jiangsu, China >> >> >> > >> >> >> > >> >> _______________________________________________ >> >> >> > Pw_forum mailing list >> >> >> > Pw_forum at pwscf.org >> >> >> > >> >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> >> > >> >> >> > >> >> >> >> _______________________________________________ >> >> >> Pw_forum mailing list >> >> >> Pw_forum at pwscf.org >> >> >> >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > >> >> > >> >> > >> >> > >> _______________________________________________ >> >> > Pw_forum mailing list >> >> > Pw_forum at pwscf.org >> >> > >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > >> > >> > >> > >> > > > > >