Dear Dr. Xavier, Yes I have got some experimental data to compare my calculations. Once I can fix the value of U and calcualte its band structure in bulk state, I will need to perform its surface state calculations to compare. Thanks for the site you provided. I will go through it for both U and supercell. Regards M. P. Ghimire NIMS
2012/4/19 Rocquefelte <Xavier.Rocquefelte at cnrs-imn.fr> > ** > Have you got any interesting experimental data to compare your > calculations and then have a better idea of the U value? > The U value is not only dependent of the element and orbital, but also on > the dimensionality and interactions (covalency) of the compound. > I would then say that the choice of the U value is always matter of > experience. You can also have a look at the note of G. Madsen and P. Novak, > which is on the WIEN2K website: > > http://www.wien2k.at/reg_user/textbooks/ > > - Notes about constraint LDA calculations to determine U (pdf) > > Regards > > Xavier > > > > > On 04/18/2012 01:59 PM, Madhav Ghimire wrote: > > Dear Dr. Xavier, > Thank you very much for your prompt reply and for your useful > comments. Now I understand how it works. > For the Platinates or iridates because of their extended orbitals, the U > value is small as explained from literature. So basing on the literatures, > I choose 1-2 eV. to check the nature of band structure. Do you think it to > be very small. If so please let me know upto how much i can use. > Will there be any influence if U=5 eV for this type of compound is chosen. > Of course, at high U with inclusion of spin-orbit coupling, it shows > interesting behavior in band structure. But I fail to plot the fat bands in > band structure to identify spin up and spin down together. > By the way, Do you know whether we can fix the value of magnetic moment of > Pt along any specified direction. > If so, I would like to know how and in which file. > Thanks again. > best wishes > M. P. Ghimire > > 2012/4/18 Rocquefelte <Xavier.Rocquefelte at cnrs-imn.fr> > >> I didn't look in detail your email but here is the solution. >> >> You should use the following case.indm file: >> >> -------------------------- >> >> -9. Emin cutoff energy >> 2 number of atoms for which density matrix is >> calculated >> 4 1 2 index of 1st atom, number of L's, L1 >> 5 1 2 dtto for 2nd atom, repeat NATOM times >> 0 0 r-index, (l,s)index >> -------------------------- >> >> and case.inorb file: >> >> -------------------------- >> >> 1 2 0 nmod, natorb, ipr >> PRATT 1.0 BROYD/PRATT, mixing >> 4 1 2 iatom nlorb, lorb >> 5 1 2 iatom nlorb, lorb >> 1 nsic 0..AFM, 1..SIC, 2..HFM >> 0.1471 0.036 U J (Ry) Note: we recommend to use U_eff = U-J >> and J=0 >> 0.1471 0.036 U J >> -------------------------- >> >> To explain, let's take an example: >> >> >> 4 1 2 index of 1st atom, number of L's, L1 >> >> Here you are saying that you will add a Hubbard term for atom 4, and >> only for one l-value, which is l = 2. >> This treatment will be applied to the valence state of Pt, i.e. the 5d >> orbital of Pt. You should not specify the principal quantum number in this >> file (n-value). >> >> I hope this reply will clarify the situation. >> >> Regards >> >> Xavier >> >> P.S.1: It is recommended to use a Ueff value, i.e. Ueff = U -J. >> In you case it will correspond to the following case.inorb file: >> >> >> -------------------------- >> >> 1 2 0 nmod, natorb, ipr >> PRATT 1.0 BROYD/PRATT, mixing >> 4 1 2 iatom nlorb, lorb >> 5 1 2 iatom nlorb, lorb >> 1 nsic 0..AFM, 1..SIC, 2..HFM >> 0.1435 0.000 U J (Ry) Note: we recommend to use U_eff = U-J >> and J=0 >> 0.1435 0.000 U J >> -------------------------- >> >> P.S.2: The Hubbard term you are using is quite small (2eV). Is it what >> you really need for your system? >> >> >> >> >> >> On 04/18/2012 01:14 PM, Madhav Ghimire wrote: >> >> Dear Dr. Xavier and wien users, >> Thank you for your kind concern to my problem. Sorry for the >> incomplete information. Let me complete my few queries and cases over which >> I am concerned to: >> (i) I am having one oxide compound with the presence of Pt atoms having >> 5d states. Because of this, I want to implement U. For the said case, we >> require case.indm and case.inorb as suggested in userguide. My edited >> case.indm file is as shown below >> -9. Emin cutoff energy >> 2 number of atoms for which density matrix is >> calculated >> 4 2 5 index of 1st atom, number of L's, L1 >> 5 2 5 dtto for 2nd atom, repeat NATOM times >> 0 0 r-index, (l,s)index >> In this indm file (marked with red color), I could not understand how >> L's=1 and , L1=2 is taken in userguide. From the the userguide, L's >> corresponds to number of l-values for which the density matrix should be >> calculated and L1 is the l-values for which the density matrix should be >> calculated. >> For the case of Pt which is 5d atom it has l=2 and n=5 with d=5 >> sublevels. Hence I substituted as shown above. But, I did not understand >> whether L's must be 2 or 5. Similar is for the case of L1. And, what about >> the r-index. >> (ii) For case.inorb, below is the input value I tried to use >> 1 2 0 nmod, natorb, ipr >> PRATT 1.0 BROYD/PRATT, mixing >> 1 2 5 iatom nlorb, lorb >> 2 2 5 iatom nlorb, lorb >> 1 nsic 0..AFM, 1..SIC, 2..HFM >> 0.1471 0.036 U J (Ry) Note: we recommend to use U_eff = U-J >> and J=0 >> 0.1471 0.036 U J >> As in case.indm, I have similar type of problem. As mentioned in >> userguide, >> nlorb; number of orbital moments for which exact exchange shall be >> calculated >> lorb: orbital numbers . >> Here, I could not differentiate between the number of orbital moments and >> orbital numbers. Does it mean the same or they are different. >> Could you kindly help to correct this two files. >> (iii) Can we fix the orbital moment of Pt. >> (iv) Can we set the minimum energy to more than 400 eV as the ground >> state energy of oxygen is approx. 400 eV. >> >> Thank you in advance >> M. P. Ghimire >> NIMS, Japan >> >> 2012/4/18 Rocquefelte <Xavier.Rocquefelte at cnrs-imn.fr> >> >>> It seems that your message is incomplete. >>> However, I am surprized to see nlorb = 5! >>> >>> If you are interested in "d" orbitals, nlorb should be 2, and if it is >>> "f" orbitals, nlorb should be 3. >>> >>> Best Regards >>> >>> Xavier >>> >>> >>> >>> >>> >>> On 04/18/2012 09:26 AM, Madhav Ghimire wrote: >>> >>> >>> Dear wien2k users, >>> I am facing some problems in putting the value of n nlorb and >>> lorb as provided in userguide. >>> -9. Emin cutoff energy >>> 2 number of atoms for which density matrix is >>> calculated >>> 4 2 5 index of 1st atom, number of L's, L1 >>> 5 2 5 dtto for 2nd atom, repeat NATOM times >>> 0 0 r-index, (l,s)index >>> for >>> -- >>> M. P. Ghimire >>> >>> >>> _______________________________________________ >>> Wien mailing listWien at >>> zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >>> >>> >>> >>> _______________________________________________ >>> Wien mailing list >>> Wien at zeus.theochem.tuwien.ac.at >>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >>> >>> >> >> >> -- >> M. P. Ghimire >> >> >> _______________________________________________ >> Wien mailing listWien at >> zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> >> >> >> _______________________________________________ >> Wien mailing list >> Wien at zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> >> > > > -- > M. P. Ghimire > > > _______________________________________________ > Wien mailing listWien at > zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > > > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > > -- M. P. Ghimire -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20120419/c9e0d7f0/attachment.htm>