Dear prasenajit thank you for your valuable inputs On Fri, Sep 11, 2009 at 2:43 PM, Prasenjit Ghosh <prasenjit.jnc at gmail.com>wrote:
> For Ti atom, the electronic configuration is [*Ar*].*3d*2.*4s*2. So the > magnetization should be 2.0 Bohr magneton due to the two electrons in the > d-orbital, which is not what you are getting from your calculation. > > Also your smearing contribution is -0.00972779 Ry (about 0.1 eV), which I > would say very high. If you would have find the correct magnetic ground > state, then this should have been 0.0 Ry. > > As far as the bulk system is concerned, I'm not sure. It depends how Ti > bulk behaves. You can search in the literature to find out what values of > degauss other people have used. > > Mixing beta doesn't effect the energy of the system. It just helps you in > convergence. > > > Prasenjit. > > 2009/9/11 udayagiri sai babu <udayagiri3 at gmail.com> > >> Dear prasenajit this is the part of my output for the posted input file. >> (smearing contribution is there! though it is small ) is the degauss value >> too high for isolated atom or it is high for bulk calculation also? because >> i use around 0.01 Ry value for all my calculations. Does the mixing beta >> value effect the energy of the system? >> >> one-electron contribution = -155.91791626 Ry >> hartree contribution = 74.49216944 Ry >> xc contribution = -14.37611953 Ry >> ewald contribution = -20.42854186 Ry >> smearing contrib. (-TS) = -0.00972779 Ry >> >> total magnetization = 3.24 Bohr mag/cell >> absolute magnetization = 3.24 Bohr mag/cell >> >> convergence has been achieved in 34 iterations >> >> >> On Fri, Sep 11, 2009 at 2:06 PM, Prasenjit Ghosh <prasenjit.jnc at gmail.com >> > wrote: >> >>> Dear Udayagiri, >>> >>> First of all it's not clear whether you have any question other than >>> whether your input file is correct. >>> >>> Now some comments about your input file: >>> >>> (a) while doing calculations for any zero dimensions you should always >>> set nosym =.true. >>> (b) Your value of degauss is too high.....you should use some value >>> around 0.001 Ry. According to my experience, doing cal. for a single atom is >>> tricky, specially when you are using a smearing. Even that doesn't confirm >>> you will get the correct ground state for the atom. So what you should do is >>> at the end of the calculation check the values of the total magnetization, >>> absolute magnetization and the smearing contribution. The last term should >>> be exactly zero. >>> (c) You don't need to set tstress and tprnfor true. >>> (c) mixing_beta= 0.7 too large.....I would put something smaller....0.3 >>> (d) I hope you have checked the convergence of ecut rho & ecutwfc. >>> >>> Prasenjit. >>> >>> 2009/9/11 udayagiri sai babu <udayagiri3 at gmail.com> >>> >>>> Hi everybody >>>> I want to calculate the cohesive energy of Titanium for that i need to >>>> calculate the energy of an isolated atom previously in the forum somebody >>>> has suggested me to do spin polarisation calculation for the isolated atom. >>>> I have written an input file accordingly some one can see and tell me if my >>>> input script is true. I have read the forum archives on this topic but they >>>> are not exactly answering my question. Can somebody please help me. >>>> * >>>> Input file for isolated atom * >>>> >>>> &control >>>> calculation = 'scf', >>>> restart_mode='from_scratch', >>>> outdir='/home/sai/temp', >>>> prefix='titanium' >>>> pseudo_dir='/home/sai/softwares/espresso-4.0.1/pseudo/', >>>> tstress = .TRUE., >>>> tprnfor = .TRUE., >>>> / >>>> &system >>>> ibrav=1 >>>> celldm(1)=20, >>>> nat=1, >>>> ntyp=1 >>>> ecutwfc=25, >>>> ecutrho=250, >>>> occupations='smearing', >>>> smearing='mv', >>>> degauss=0.010000 >>>> nspin=2 >>>> starting_magnetization(1)=0.2 >>>> / >>>> &electrons >>>> conv_thr=1.D-8, >>>> diagonalization='david', >>>> mixing_mode='plain', >>>> mixing_beta= 0.7, >>>> / >>>> ATOMIC_SPECIES >>>> Ti 47.867 Ti.pbe-sp-van_ak.UPF >>>> ATOMIC_POSITIONS (crystal) >>>> Ti 0.00000000 0.00000000 0.00000000 >>>> K_POINTS GAMMA >>>> >>>> -- >>>> U.Saibabu >>>> PhD student, >>>> Deformation mechanisms modeling group, >>>> Materials engineering department, >>>> IISc Bangalore, >>>> India. >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> Pw_forum at pwscf.org >>>> http://www.democritos.it/mailman/listinfo/pw_forum >>>> >>>> >>> >>> >>> -- >>> PRASENJIT GHOSH, >>> POST-DOC, >>> ROOM NO: 265, MAIN BUILDING, >>> CM SECTION, ICTP, >>> STRADA COSTERIA 11, >>> TRIESTE, 34104, >>> ITALY >>> PHONE: +39 040 2240 369 (O) >>> +39 3807528672 (M) >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> Pw_forum at pwscf.org >>> http://www.democritos.it/mailman/listinfo/pw_forum >>> >>> >> >> >> -- >> U.Saibabu >> PhD student, >> Deformation mechanisms modeling group, >> Materials engineering department, >> IISc Bangalore, >> India. >> >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > > > -- > PRASENJIT GHOSH, > POST-DOC, > ROOM NO: 265, MAIN BUILDING, > CM SECTION, ICTP, > STRADA COSTERIA 11, > TRIESTE, 34104, > ITALY > PHONE: +39 040 2240 369 (O) > +39 3807528672 (M) > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- U.Saibabu PhD student, Deformation mechanisms modeling group, Materials engineering department, IISc Bangalore, India. -------------- next part -------------- An HTML attachment was scrubbed... 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