Dear Tran and F. Gerhard Many thanks for your help. With me the Cohesive Energies for NI and Fe are 5.53 eV/atom and 5.92eV/atom
On Thu, Jan 1, 2015 at 3:36 PM, <t...@theochem.tuwien.ac.at> wrote: > From the total energies it's difficult to say. It's better to > compare the cohesive energies. My cohesive energies for Fe and Ni > with the WC functional are 5.54 and 5.38 eV/atom, respectively, with > an error bar of 0.05 eV/atom maximum. In this paper you can find > PBE cohesive energies calculated with the VASP code (my PBE values > agree very well with them): > http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.214102 > > You have to know which error is acceptable for your purposes. > > > > On Thu, 1 Jan 2015, Muhammad Sajjad wrote: > > Dear Tran Thank you for your further help. I am also attaching here with >> the structure file. Please let know the E0 values you calculated for Ni and >> Fe. With me >> these values are -3040.43215615 and -2544.39535597 (in Ry) respectively. >> >> On Tue, Dec 30, 2014 at 4:52 AM, <t...@theochem.tuwien.ac.at> wrote: >> Hi, >> >> The struct file that I used is attached. For my purpose, the size of >> the unit cell was large enough to avoid spurious interactions >> between >> neighbouring cells. Note that a, b and c are different in order to >> avoid >> to high symmetry. >> >> F. Tran >> >> On Mon, 29 Dec 2014, Muhammad Sajjad wrote: >> >> Dear Prof. Marks and F. TranThank you so much for your >> helpful suggestions. I was already doing the spin polarization >> calculations. I >> have got the convergence >> by using >> mixing factor 0.1, starting calculation with PRATT and then >> switched to MSR1 after 7 cycles, and the command runsp_lapw -cc 0.00001 >> -in1ef -i 150 >> The obtained magnetic moment was 2.00009. >> >> Dear Tran I would really appreciate if you share some more >> details about case.struct file. It will definitely be helpful for me as well >> as for others. >> >> Kind Regards >> Dr. Sajjad >> >> On Mon, Dec 29, 2014 at 3:50 AM, <t...@theochem.tuwien.ac.at> >> wrote: >> The calculation for an isolated atom with a code which >> uses periodic >> boundary conditions (like WIEN2k) is not trivial. This >> is what I have done >> recently for most atoms of the periodic table >> (excluding f-systems), and >> for some of the transition-metal atoms this was >> extremely difficult to >> achieve convergence. >> >> A few hints (that I used): >> >> 1) It is important (and necessary depending on the >> atom) to reduce the >> symmetry from cubic to, e.g., orthorhombic to be able >> to access the >> electronic configuration with the lowest energy (this >> is the procedure >> followed by several research groups like VASP for >> instance). >> If necessary I can give more details about the >> case.struct that I used. >> >> 2) lapw0 requires a lot of memory, while lapw1 requires >> both >> memory and time. To reduce computer time for lapw1, I >> was using >> iterative digonalization (this was my command for all >> atoms): >> runsp_lapw -ec 0.0001 -cc 0.0001 -it -i 1000 -NI >> >> 3) For the Ni atom the magnetic moment should be 2: >> :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 2.00238 >> >> 4) I was using the default setting for mixer. >> >> F. Tran >> >> On Sun, 28 Dec 2014, Laurence Marks wrote: >> >> >> Also, only 1 k-point (Gamma), an RMT and RKMax >> similar to what you use for >> bulk Ni, particularly as I assume you are doing >> the calculation to get an >> enthalpy of formation. You may have to use the >> mpi versions as it is >> probably too large for a non-mpi run. >> >> If you are doing WC+U (or -ineece) the U (or >> on-site hybrid) removes the >> phase transition so convergence should be simple. >> >> Straight WC is not a simple calculation because >> the physics for an isolated >> Ni atom is wrong. With wrong physics there is in >> fact no guarantee that the >> calculation will ever converge! >> >> ___________________________ >> Professor Laurence Marks >> Department of Materials Science and Engineering >> Northwestern University >> www.numis.northwestern.edu >> MURI4D.numis.northwestern.edu >> Co-Editor, Acta Cryst A >> "Research is to see what everybody else has seen, >> and to think what nobody >> else has thought" >> Albert Szent-Gyorgi >> >> On Dec 28, 2014 11:47 AM, "Laurence Marks" < >> l-ma...@northwestern.edu> wrote: >> >> You almost certainly need to run spin >> polarized, probably MSR1 >> (GREED 0.1), TEMPS (room temp). The >> convergence is complicated >> for WC (& simple GGAs) due to an electronic >> phase transition >> between sp & d occupation near the fixed >> point. >> >> ___________________________ >> Professor Laurence Marks >> Department of Materials Science and >> Engineering >> Northwestern University >> www.numis.northwestern.edu >> MURI4D.numis.northwestern.edu >> Co-Editor, Acta Cryst A >> "Research is to see what everybody else has >> seen, and to think >> what nobody else has thought" >> Albert Szent-Gyorgi >> >> On Dec 28, 2014 10:47 AM, "Muhammad Sajjad" >> <sajja...@gmail.com> >> wrote: >> Dear Users I am running SCF >> calculation for Ni with >> lattice constant of 30 Bohr and using >> WC-GGA. The >> calculation is not converging even >> upto 100 >> iterations and more. To solve the >> problem I have >> performed following steps >> >> switched to TEMPS = 0.005 from TETRA >> Changed MSR1 to PRATT >> changed mixing factor (increase and decrease from >> 0.2) >> >> Thanking in advance. >> >> Dr. Sajjad >> >> >> >> _______________________________________________ >> Wien mailing list >> Wien@zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> SEARCH the MAILING-LIST at: http://www.mail-archive.com/ >> wien@zeus.theochem.tuwien.ac.at/index.html >> >> >> >> >> _______________________________________________ >> Wien mailing list >> Wien@zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> SEARCH the MAILING-LIST at: http://www.mail-archive.com/ >> wien@zeus.theochem.tuwien.ac.at/index.html >> >> >> >> > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html > >
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