I want electronic and optical properties of cerium oxide do I check my inputs to check the correct sheet is Nano?
On Thu, Aug 6, 2015 at 7:17 PM, Ari P Seitsonen <[email protected]> wrote: > > Dear Ben Liew, > > If one is lucky, the system might converge to the right magnetic ground > state with a "random guess". Yet if the system has several local minima, or > the initial guess is very far from the true magnetic ordering, one might > get very bad initial densities (total and spin density, or spin-up and > spin-down densities), leading to difficulties in convergence and maybe even > divergence. Yet-another-issue might be bad description of the electronic > structure with the GGA's, I seem to remember that in the case of MnO2 the > GGA gives reasonable results, even if the electronic band gap is naturally > much too small (and using the smearing should help to get a convergence > anyway). > > I would myself start by trying a weakly ferromagnetic guess (for example > 'starting_magnetization(1) = 0.2' and seeing if something happens. If it > converges, or doesn't, I would then see if an anti-ferromagnetic solution > might also make sense (two types of Mn atoms in cell, etc). > > Greetings, > > apsi > > > -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=- > Ari Paavo Seitsonen / [email protected] / http://www.iki.fi/~apsi/ > Ecole Normale Supérieure (ENS), Département de Chimie, Paris > Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935 > > > On Wed, 5 Aug 2015, ben liew wrote: > > Dear Bahadir, >> Thanks for your comments. I will try using a lower mixing_beta and change >> the mixing_mode='local-TF'. >> >> Dear Ari Paavo Seitsonen, >> >> Thanks. I have no knowledge on the magnetism of my system. How could I >> know >> what value of starting_magnetization that I should use in my slab >> calculation? Does the starting_magnetization affect the convergence of my >> calculation? >> >> Thank you >> >> >> Best Regards, >> Ben Liew >> Ph.D Student >> Fuel Cell Institute, >> The National University of Malaysia, >> 43600 Bangi, >> Selangor, Malaysia. >> Contact no. : +6016 552 0878 >> Email : [email protected] >> >> On Wed, Aug 5, 2015 at 5:20 PM, Bahadır salmankurt <[email protected] >> > >> wrote: >> Dear Ari P Seitsonen, >> I didnt know that mixing_mode='local-TF' effect initial magnetic >> moments. thanks for this. By the way, Do you know about e field >> configuration? for example, for slab + molecule systems whose atomic >> positions are in 0.5 and 0.65 along z direction , respectively, what >> must values of the emaxpos and eopreg be? >> Bests >> Bahadir >> >> 2015-08-05 10:59 GMT+03:00 Ari P Seitsonen <[email protected]>: >> >> Dear Ben Liew, >> >> Without looking at the structure itself, adding to the >> previous comment about the algorithm for mixing, you have >> not really given any initial magnetic moments even if you >> have 'nspin = 2': The 'starting_magnetization(1) = 0.0' >> does not give any preferential spin ordering. Do you know >> something about this, is the system expected to be >> ferromagnetic, antiferromagnetic, ...? >> >> Tiny issues, I usually do the first calculation without >> the surface dipole as it makes the convergence always a >> bit trickier; and your >> 'B ~= 2 * A', but you give the same number of k points in >> both directions. (I usually tend to use smearing schemes >> where the occupations are guaranteed to be in the physical >> range of [0:1], but this is just a personal preference and >> should thus be ignored) >> >> Greetings, >> >> apsi >> >> >> -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=* >> =- >> Ari Paavo Seitsonen / [email protected] / >> http://www.iki.fi/~apsi/ >> Ecole Normale Supérieure (ENS), Département de Chimie, >> Paris >> Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935 >> >> >> On Wed, 5 Aug 2015, ben liew wrote: >> >> Dear PWSCF users, >> >> Hi, I am a new user of Pwscf. I am working on >> slab calculation for pyrolusite MnO2 (110) >> surface with 3 atomic layers calculation and >> fixed bottom 2 layers and only top atomic >> layer is allowed to be relaxed. I have also >> include the dipole correction for the >> calculation to counteract with the interaction >> between slabs. However, my calculation doesn't >> seems to be converged as the scf accuracy is >> not decreasing over each iteration. Below is >> the estimated scf accuracy after hundreds of >> iterations, it is not converging >> >> estimated scf accuracy < >> 373.64728976 Ry >> estimated scf accuracy < >> 106.52177156 Ry >> estimated scf accuracy < >> 96.97567125 Ry >> estimated scf accuracy < >> 207.03807187 Ry >> estimated scf accuracy < >> 132.53045831 Ry >> estimated scf accuracy < >> 77.19101827 Ry >> estimated scf accuracy < >> 112.41885075 Ry >> estimated scf accuracy < >> 93.27430429 Ry >> estimated scf accuracy < >> 116.68049786 Ry >> estimated scf accuracy < >> 587.09711027 Ry >> estimated scf accuracy < >> 374.45312501 Ry >> estimated scf accuracy < >> 106.89811469 Ry >> estimated scf accuracy < >> 96.84898888 Ry >> estimated scf accuracy < >> 207.83006869 Ry >> estimated scf accuracy < >> 132.74588293 Ry >> estimated scf accuracy < >> 77.09445200 Ry >> estimated scf accuracy < >> 112.41688597 Ry >> estimated scf accuracy < >> 93.57796273 Ry >> estimated scf accuracy < >> 116.25663912 Ry >> estimated scf accuracy < >> 587.39968959 Ry >> estimated scf accuracy < >> 374.91438307 Ry >> estimated scf accuracy < >> 106.71641516 Ry >> estimated scf accuracy < >> 96.75392736 Ry >> >> I have include my input file as followed. Can >> anyone tell me is that any problem with my >> input file? >> >> &control >> calculation = 'relax' >> tstress=.true. >> tprnfor=.true. >> >> pseudo_dir='/home/ben/Downloads/espresso-5.1.2/pseudo' >> outdir='./vc3' >> prefix='pyrolusite' >> tefield=.true. >> dipfield=.true. >> / >> &system >> ibrav=8, >> A=2.8563, B=6.2199, C=20.0 >> nat=18, ntyp=2, >> starting_magnetization(1)=0.0 >> nspin=2 >> ecutwfc=37.0 >> ecutrho=250.0 >> occupations='smearing' >> smearing='m-v' >> degauss=0.01 >> edir=3 >> emaxpos=0.5 >> eopreg=0.1 >> eamp=0.001 >> / >> &electrons >> electron_maxstep=500 >> conv_thr=1.0d-6 >> mixing_beta=0.7 >> / >> &ions >> ion_dynamics='bfgs' >> / >> ATOMIC_SPECIES >> Mn 54.9380 Mn.pbe-spn-kjpaw_psl.0.3.1.UPF >> O 15.9994 O.pbe-kjpaw.UPF >> ATOMIC_POSITIONS (angstrom) >> O 1.428129 3.109734 0.000000 0 0 >> 0 >> O 1.428129 0.000241 0.652526 0 0 >> 0 >> Mn 1.428129 3.109896 1.883398 0 0 >> 0 >> O 0.000000 1.885646 1.883398 0 0 >> 0 >> O 0.000000 4.334118 1.883398 0 0 >> 0 >> Mn 0.000000 0.000062 1.883398 0 0 >> 0 >> O 0.000000 5.014614 4.987475 0 0 >> 0 >> O 0.000000 1.205401 4.987475 0 0 >> 0 >> Mn 0.000000 3.109816 4.987475 0 0 >> 0 >> Mn 1.428129 0.000027 4.987475 0 0 >> 0 >> O 1.428129 3.109734 3.767387 0 0 >> 0 >> O 1.428129 0.000241 3.114269 0 0 >> 0 >> O 1.428129 3.109734 6.207560 >> O 1.428129 0.000241 6.860698 >> Mn 1.428129 3.109896 8.091569 >> O 0.000000 1.885646 8.091569 >> O 0.000000 4.334118 8.091569 >> Mn 0.000000 0.000062 8.091569 >> K_POINTS (automatic) >> 5 5 1 0 0 0 >> >> Your comments and suggestion is much >> appreciated.Thank you. >> >> >> Best Regards, >> Ben Liew >> Ph.D Student >> Fuel Cell Institute, >> The National University of Malaysia, >> 43600 Bangi, >> Selangor, Malaysia. >> Contact no. : +6016 552 0878 >> Email : [email protected] >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> >> >> >> > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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