[Wien] inclmcopy setup

Peter Blaha pblaha at theochem.tuwien.ac.at
Tue Feb 22 09:29:49 CET 2011


Ok:
You want an AFM structure, where Pu1=Pu2=up, Pu3=dn  = Pu4  (of the nonmagnetic structure).

It is a bit lengthy, but thats the way to do:

1) You would start with a struct file (because this obeys your "wishes" above) like:

puo2
P   LATTICE,NONEQUIV.ATOMS:  3
MODE OF CALC=RELA unit=bohr
  10.318287 10.318287 10.318287 90.000000 90.000000 90.000000
ATOM  -1: X=0.00000000 Y=0.00000000 Z=0.00000000
           MULT= 2          ISPLIT=-2
ATOM  -1: X=0.50000000 Y=0.50000000 Z=0.00000000
Pu1        NPT=  781  R0=0.0000010 RMT=    2.17     Z: 94.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
ATOM  -3: X=0.50000000 Y=0.00000000 Z=0.50000000
           MULT= 2          ISPLIT= 8
       -3: X=0.00000000 Y=0.50000000 Z=0.50000000
Pu3        NPT=  781  R0=0.0000010 RMT=    2.17     Z: 94.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
ATOM  -4: X=0.25000000 Y=0.25000000 Z=0.25000000
           MULT= 8          ISPLIT= 8
       -4: X=0.75000000 Y=0.75000000 Z=0.25000000
       -4: X=0.75000000 Y=0.25000000 Z=0.75000000
       -4: X=0.25000000 Y=0.75000000 Z=0.75000000
       -4: X=0.25000000 Y=0.25000000 Z=0.75000000
       -4: X=0.75000000 Y=0.75000000 Z=0.75000000
       -4: X=0.75000000 Y=0.25000000 Z=0.25000000
       -4: X=0.25000000 Y=0.75000000 Z=0.25000000
O          NPT=  781  R0=0.0001000 RMT=    1.92     Z:  8.0
LOCAL ROT MATRIX:    0.0000000-0.7071068-0.7071068
                      0.0000000-0.7071068 0.7071068
                     -1.0000000 0.0000000 0.0000000
   00      NUMBER OF SYMMETRY OPERATIONS

2) When running sgroup, it reduces the structure by a factor of two and builds a tetragonal lattice:

puo2
P   LATTICE,NONEQUIV.ATOMS:  3 123 P4/mmm
MODE OF CALC=RELA unit=bohr
   7.296131  7.296131 10.318287 90.000000 90.000000 90.000000
ATOM  -1: X=0.00000000 Y=0.00000000 Z=0.00000000
           MULT= 1          ISPLIT=-2
Pu1        NPT=  781  R0=0.0000010 RMT=    2.17     Z: 94.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
ATOM  -2: X=0.50000000 Y=0.50000000 Z=0.50000000
           MULT= 1          ISPLIT=-2
Pu2        NPT=  781  R0=0.0000010 RMT=    2.17     Z: 94.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
ATOM  -3: X=0.00000000 Y=0.50000000 Z=0.25000000
           MULT= 4          ISPLIT= 8
       -3: X=0.50000000 Y=0.00000000 Z=0.25000000
       -3: X=0.00000000 Y=0.50000000 Z=0.75000000
       -3: X=0.50000000 Y=0.00000000 Z=0.75000000
O 1        NPT=  781  R0=0.0001000 RMT=    1.92     Z:  8.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
   16      NUMBER OF SYMMETRY OPERATIONS

This file has a "rotated" coordinate system (x and y are rotated by 45 degrees).

3) In order to work with afminput, you need a "nonmagnetic" file in the identical coordinate system,
i.e. in the above struct file you make both Pu "equivalent". However, for such a file sgroup would
dedect it to be fcc cubic again (with a rotated coordinate system). To enforce a tetragonal lattice,
you change the c-parameter by some small number (see below)

puo2
P   LATTICE,NONEQUIV.ATOMS:  2 123 P4/mmm
MODE OF CALC=RELA unit=bohr
   7.296131  7.296131 11.318287 90.000000 90.000000 90.000000
ATOM  -1: X=0.00000000 Y=0.00000000 Z=0.00000000
           MULT= 2          ISPLIT=-2
ATOM  -1: X=0.50000000 Y=0.50000000 Z=0.50000000
Pu2        NPT=  781  R0=0.0000010 RMT=    2.17     Z: 94.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
ATOM  -3: X=0.00000000 Y=0.50000000 Z=0.25000000
           MULT= 4          ISPLIT= 8
       -3: X=0.50000000 Y=0.00000000 Z=0.25000000
       -3: X=0.00000000 Y=0.50000000 Z=0.75000000
       -3: X=0.50000000 Y=0.00000000 Z=0.75000000
O 1        NPT=  781  R0=0.0001000 RMT=    1.92     Z:  8.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
   16      NUMBER OF SYMMETRY OPERATIONS

4) Running sgroup for this file, detecs a bc tetragonal cell, again with 16 operations,
which should be your case.struct_supergroup

puo2
B   LATTICE,NONEQUIV.ATOMS:  2 139 I4/mmm
MODE OF CALC=RELA unit=bohr
   7.296131  7.296131 10.318287 90.000000 90.000000 90.000000
ATOM   1: X=0.00000000 Y=0.00000000 Z=0.00000000
           MULT= 1          ISPLIT=-2
Pu1        NPT=  781  R0=0.0000010 RMT=    2.17     Z: 94.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
ATOM   2: X=0.00000000 Y=0.50000000 Z=0.25000000
           MULT= 2          ISPLIT= 8
        2: X=0.50000000 Y=0.00000000 Z=0.25000000
O 1        NPT=  781  R0=0.0001000 RMT=    1.92     Z:  8.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                      0.0000000 1.0000000 0.0000000
                      0.0000000 0.0000000 1.0000000
   16      NUMBER OF SYMMETRY OPERATIONS

5) When you run    x afminput with these files, it says:

case.struct_supergroup present
  The super and subgroups are KLASSENGLEICH
  You must specify a translation vector which transforms the
  spin-up into the spin-dn atom (e.g.: 0.5,0.5,0.5 for AFM bcc Cr)!

And you should obviously put (because this is the translation which connects
the Pu at the origin with the one at the center of the cell):
0.5,0.5,0.5

And this creates the required case.inclmcopy_st

------------------
If this is too complicated, just stop after sgroup has generated the proper AF tetragonal struct file,
(step 2), forget about the supergroup-file and runafm_lapw, but use runsp_lapw instead. It will give (if it wants
to be AFM) the same results, but with a doubled computational effort, which is, however, negligible for
these small cells.

Am 22.02.2011 02:41, schrieb hao wang:
> Dear Prof. Blaha and users,
>    Thank you very much.
>    The PuO2 AF structure file built along (001). 4 Pu have the same symmetry and Pu1=Pu2=up, Pu3=dn. the inst file is attached. the net spin is zero. So please tell me where is wrong.
>

-- 

                                       P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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