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 insufficient sampling, not a small error. Solution 1 - if you do not want to think, ever, in your life, use 0.01 Ry of m-v or m-v smearing, and increase the k-point sampling until the difference in energy between G and C type is converged. Solution 2 - plot the energy difference between G and C as a function of smearing, for m-v smearing of 0.005, 0.010, 0.015, 0.020, 0.025, and with at least 3 or 4 k-point sampling. Use the discussion from http://theossrv1.epfl.ch/Main/ElectronicTemperature to understand what to do. nicola On 30/06/2015 17:07, paresh rout wrote: > 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 > like (G-type, C-type). The total energy (SCF) for G-type and C-type are > in reverse ordering for different smearing technique (*G-type is the > ground state for* *MV smearing and C-type is the ground state for FD*). > But when I reduced the value of degauss of *MV to 0.008 *I got the same > ordering as FD. > I am very confused about the smearing technique . I have also read Prof. > Nicola's thesis about smearing but there I did not get rid of my > confusion also I did not find about FD technique . Can anybody kindly > tell me about the right smearing technique which I can use for the spin > polarized calculation ? Any reply would be highly appreciated. > > > Kind Regards > Paresh Chandra Rout > Research Scholar > INDIAN INSTITUTE OF SCIENCE EDUCATION AND RESEARCH, BHOPAL > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- ---------------------------------------------------------------------- Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL Director, National Centre for Competence in Research NCCR MARVEL, EPFL _______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum