Dear Ari Paavo Seitsonen, Thanks for your advice. I will try your suggestion and see what will happen.
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 Fri, Aug 7, 2015 at 1:28 AM, Mahya Zare <[email protected]> wrote: > 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 >> > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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