Hello Krishnaveni Parthasarathy

Yes you can - though admittedly I did not look up your reference, and I might misinterprete your idea of 'layered AFM'. And I suppose you consider collinear magnetic moments. If that is not the case you might look into the (unsupported) WienNCM.

In general, study the UG, especially the chapters on AFM calculations.

You can think of any collinear AFM as ferromagnetic layers stacked along one particular crystalographic direction, the direction to the nearest antiparallel neighbor. For calculations with Wien2k you need a .strcut with a unit cell that has at least two magnetic atoms along that direction (perhaps from supercell if the crystalografic primitve cell is not large enough).

Since you want them to be magnetically inequivalent the two have to be on inequievalent crystalografic sites. If they are on crystalografic equivalent positions you have to split the position and number the atoms to tell Wien2k that they are not same (perhaps Mn1 and Mn2). Note that this results in a different symmetry of your structure.

If you want to compare total energies for different magnetic structures be careful to calculate all of them on the same crystalographic unit cell, changing only in the initialization which magnetic atom belongs to the group pointing 'up' and which one to the group pointing 'down'. If you have, for example, constructed a supercell with four inequivalent Mn-sites Mn1 .. Mn4, you can calculate AFM structures corresponding to Mn1, Mn2 up and Mn3, Mn4 down, or Mn1,3 up and Mn2,4 down, or ... This will correspond to ferromagnetic layers of Mn1, Mn2 stacked with antiparallel ferromagnetic layers Mn3,4, or ferromagnetic layers of Mn1,3 ... Not all of these arrangements are necessarily different. If the direction Mn1 - Mn2 is symmetry related to the one Mn1-Mn3 in the underlying crystalografic lattice, then there is no need to calculate with the stacking in these two equivalent directions. And obviously, for a complicated AF wave vector (the direction of the stacking), you will need large supercells so think, before you start.

Good luck,

Martin Pieper


---
Dr. Martin Pieper
Karl-Franzens University
Institute of Physics
Universitätsplatz 5
A-8010 Graz
Austria
Tel.: +43-(0)316-380-8564


Am 28.09.2015 18:43, schrieb Krishnaveni. S:
Ref: Electronic Structure, Chemical Bonding, and Finite-Temperature
Magnetic Properties of Full Heusler Alloys

Authors: YASEMIN KURTULUS, MICHAEL GILLEßEN, RICHARD DRONSKOWSKI*

DOI 10.1002/jcc.20308

online in Wiley InterScience (www.interscience.wiley.com [1]).

Ref to the article (Page 93) mentioned above, I understand that one
can perform layered calculation in AFM calculations.

In page 93, the authors have mentioned as below: “Here, the symmetry
has been slightly reduced to obtain a model in which the Mn planes can
be treated separately. This particular alignment is characterized by
alternating planes along (001) of spin-up and spin-down manganese
moments, and the identically oriented manganese moments within each
plane are coupled by the p orbitals of the Z elements. An alternative
anti ferromagnetic model with alternating magnetic planes along (111)
is also thinkable, but earlier total-energycalculations11 have already
clarified that the (001) model is characterized by lower energies in
almost all cases.”

 The author has specified that these calculations have been done in
VASP. Can some one help me understand if it is possible to perform
similar type of calculations in Wien2k?

--

Thanks and regards

Krishnaveni Parthasarathy
8939675012

Links:
------
[1] http://www.interscience.wiley.com

_______________________________________________
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

Reply via email to