[Pw_forum] Smearing Problem

Dear all, I am dealing with a transition metal oxide compound (ABO3), Where I use cold smearing *m-v(0.02)* for geometry optimization and for total energy calculation I use *f-d (0.00184*) at the final optimized structure. I have calculated the total energy for various type of magnetic ordering lik

Re: [Pw_forum] Smearing Problem

Dear Paresh, maybe this is easier to follow: http://theossrv1.epfl.ch/Main/ElectronicTemperature The main concept is that with very small smearing you need *a lot* of k-points to perform the correct Brillouin zone integrations - so with a 0.00184 smearing you have a *large* error due to ins

Re: [Pw_forum] Smearing Problem

Thank you very much sir. That was a very helpful reply. Now I understand smearing. Just one more query, I did a convergence test with k-point sampling by fixing the F-D smearing value to 0.00184 and the energy difference between C-type and G-type seems to be converged (I have attached the conver

Re: [Pw_forum] Smearing Problem

Sorry sir in the previous plot the energy difference was not per atom. So here I am attaching the Corrected plot. My system contains 20 atom. On Wed, Jul 1, 2015 at 6:09 PM, paresh rout wrote: > Thank you very much sir. That was a very helpful reply. Now I understand > smearing. Just one more q

Re: [Pw_forum] Smearing Problem

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Re: [Pw_forum] Smearing Problem

Hi Paresh, all good - but are you sure the units are mRy? A difference of 0.06 mRy /atom is super small (11604K=1eV), so we are talking about 10K difference, lost in the noise of the errors of approximate functionals, entropic effects, etc... Anyhow, if you want the computational "truth" you co

Re: [Pw_forum] Smearing Problem

Hello Sir, The units are in mRy. I tried with halving and doubling the F-D smearing value and the energy difference remains same (0.06mRy/atom) using largest k-point sampling. Can I rely on this F-D smearing (0.00184) results now ? I am also doing a convergent test on MV smearing with the largest

Re: [Pw_forum] Smearing Problem

On 02/07/2015 20:24, paresh rout wrote: > Hello Sir, > The units are in mRy. I tried with halving and doubling the F-D smearing > value and the energy difference remains same (0.06mRy/atom) using > largest k-point sampling. Can I rely on this F-D smearing (0.00184) > results now ? I am also doing

Re: [Pw_forum] Smearing Problem

Hi Dear experts pwscf I have questions about this topic. Prof. Nicola two solution suggested. For every solution for every calculation must be relaxed or scf calculation? This is so long calculation for big system for determine best smearing. another Question about (-TS) is must be zero? Whic

Re: [Pw_forum] Smearing Problem

Science and Technology of China/Department of Physics No.1088,Xueyuan Road, Shenzhen,Guangdong -- Original -- From: "Elham"; Date: Wed, Jul 8, 2015 04:28 PM To: "pw_forum"; Subject: Re: [Pw_forum] Smearing Problem Hi Dear e

Re: [Pw_forum] Smearing Problem

Excuseme. On my experience I prefer to use smearing gaussian because this smearing is more stable than the others when the density of states have a height structure, for example peaks of density of states near the fermi level. This smearing needs a good density of k points but is stable. In the

Re: [Pw_forum] Smearing Problem

Thanks so much dear PANG Rui and Arellano for sharing your experience with me I agree with you about gaussian smearing. I for determine degauss, amont of deguss is good that (-TS) is zero and tot magnetization is converged for magnetic systems. I use 0.001 Ry for pure surface relaxation is good an

Re: [Pw_forum] Smearing Problem

Thanks so much dear PANG Rui and Arellano for sharing your experience with me I agree with you about gaussian smearing. I for determine degauss, amont of deguss is good that (-TS) is zero and tot magnetization is converged for magnetic systems. I use 0.001 Ry for pure surface relaxation is good an

Re: [Pw_forum] Smearing Problem

Dear Elham, I think it's all on the right track. In general, your smearing values are very small (I hesitate to go below 0.01 Ry); with regard to the figure you have, it's for a system where forces are very close to zero, so it's not super-useful. But the sense of the sentence is that as you

Re: [Pw_forum] Smearing Problem

Dear Nicola Thanks so much . According to this graph and your words I use smearing 0.001 Ry with kpoint 2*2*1 is enough to get a good result. or I must be increase smearing ? I have other problem with smearing and magnetic properties This smearing and kpoint is good for pure surface but when I