[Re:05] Regarding afm fcc-Fe convergance and higher total energy values compared to bcc fm-Fe

Posted on : November 22, 2018 (Thu) 01:57:20

by Qais Ali

Dear KKR users,
As suggested to me by Mr. Hitoshi to summarize here about AFM calculation of Fe. Following is the procedure to be followed.

First you have to make an input file like given below;
c-----------------bcc-Fe-fm------------------------------
go data/fe_bcc_FM
c------------------------------------------------------------
c brvtyp a c/a b/a alpha beta gamma
sc 4.95 , , , , , ,
c------------------------------------------------------------
c edelt ewidth reltyp sdftyp magtyp record
0.001 1.0 nrl mjw mag init
c------------------------------------------------------------
c outtyp bzqlty maxitr pmix
update 5 150 0.015
c------------------------------------------------------------
c ntyp
2
c------------------------------------------------------------
c type ncmp rmt field mxl anclr conc
Fe1 1 1 0.0 2
26 100
Fe2 1 1 0.0 2
26 100
c------------------------------------------------------------
c natm
2
c------------------------------------------------------------
c atmicx(in the unit of a) atmtyp
0 0 0 Fe1
0.5 0.5 0.5 Fe2
c------------------------------------------------------------
c moment
c 0.0
c----------------------------------------------------------

After you achieve the convergence you have to make following changes in your input file
c-----------------bcc-Fe-fm------------------------------
fsm data/fe_bcc_AFM
c------------------------------------------------------------
c brvtyp a c/a b/a alpha beta gamma
sc 4.95 , , , , , ,
c------------------------------------------------------------
c edelt ewidth reltyp sdftyp magtyp record
0.001 1.0 nrl mjw mag 2nd
c------------------------------------------------------------
c outtyp bzqlty maxitr pmix
update 5 150 0.015
c------------------------------------------------------------
c ntyp
2
c------------------------------------------------------------
c type ncmp rmt field mxl anclr conc
Fe1 1 1 0.0 2
26 100
Fe2 1 1 0.0 2
26 100
c------------------------------------------------------------
c natm
2
c------------------------------------------------------------
c atmicx(in the unit of a) atmtyp
0 0 0 Fe1
0.5 0.5 0.5 Fe2
c------------------------------------------------------------
c moment
0.0
c----------------------------------------------------------

Then go to util and arrange the spin of atoms according to your AFM configuration and run the inputsample file. After this you again have to run input file and hence you can achieve the energy and magnetic moment for your desired structure.

Regards,
Qais