[Wien] (no subject)
Peter Blaha
pblaha at theochem.tuwien.ac.at
Mon Apr 27 09:24:14 CEST 2009
> On execution of x sgroup, the following error message occurs:
>
> Error: duplicated atoms found Atom #3 and #9 coincide.
> ATOM 2: X=0.25000000 Y=0.75000000 Z=0.00000000
> ATOM 3:X= 0.75000000 Y=0.75000000 Z=0.50000000
For sure, sgroup is right. The two positions differ only by the F-centering (0.5,0,0.5)
AND ARE THUS IDENTICAL POSITIONS.
"Fractional occupancies" as specified in X-ray structures are not possible.
You must split the 16d position, which will reduce symmetry and you no longer have SG227.
"16d" in fcc means you have "4-nonequivalent" atoms.
Now occupy 2 of them with Mn and 2 other with Co. This gives you the simplest possible
ordered "supercell".
To achieve this, remove the "spacegroup 227", but just specify a F-centered lattice.
Of course, this is a first, very crude model of a "disordered" compound and you may want to test
arrangements with larger supercells.
------------------------------------------------------
> Then after executing spin polarized calculation, I got the following
> information about the magnetic moment in case.scf file:
>
> MAGNETIC MOMENTS OF MIXED CHARGE DENSITY
>
> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL = 1.02591
>
> :MMI001: MAGNETIC MOMENT IN SPHERE 1 = 0.28125
>
> :MMI002: MAGNETIC MOMENT IN SPHERE 2 = 3.80049
>
> :MMI003: MAGNETIC MOMENT IN SPHERE 3 = 0.03426
>
> :MMTOT: TOTAL MAGNETIC MOMENT IN CELL = 10.02597
>
>
>
> which seems to be inconsistent.
What is inconsistent ???? You must consider the multiplicity of the atoms!
> I am trying to study the Co2MnO4 system using Wien2k. It has a inverse
> spinel structure with ionic configuration [Co^2+ ]_8a [Co^3+ Mn^3+ ]_16d
> [O_4 ]_32e , where 8a, 16d and 32e are the Wyckoff positions and 8a
> denotes the tetrahedral site and 16d denotes the octahedral site. I am
> unable to define the required atomic positions.
>
> I have used the following case.struct file:
>
> Co2MnO4
>
> F LATTICE,NONEQUIV.ATOMS: 4227_Fd-3m
>
> MODE OF CALC=RELA unit=ang
>
> 15.652608 15.652608 15.652608 90.000000 90.000000 90.000000
>
> ATOM -1: X=0.12500000 Y=0.12500000 Z=0.12500000
>
> MULT= 2 ISPLIT= 8
>
> ATOM -1:X= 0.87500000 Y=0.87500000 Z=0.87500000
>
> Co NPT= 781 R0=0.00005000 RMT= 1.9500 Z: 27.0
>
> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
>
> 0.0000000 1.0000000 0.0000000
>
> 0.0000000 0.0000000 1.0000000
>
> ATOM 2: X=0.25000000 Y=0.75000000 Z=0.00000000
>
> MULT= 4 ISPLIT= 8
>
> ATOM 2:X= 0.25000000 Y=0.50000000 Z=0.25000000
>
> ATOM 2:X= 0.00000000 Y=0.25000000 Z=0.75000000
>
> ATOM 2:X= 0.00000000 Y=0.50000000 Z=0.00000000
>
> Co NPT= 781 R0=0.00005000 RMT= 1.9500 Z: 27.0
>
> LOCAL ROT MATRIX: 0.0000000 0.0000000 0.0000000
>
> 0.0000000 0.0000000 0.0000000
>
> 0.0000000 0.0000000 0.0000000
>
> ATOM 3: X=0.50000000 Y=0.50000000 Z=0.50000000
>
> MULT= 4 ISPLIT= 8
>
> ATOM 3:X= 0.50000000 Y=0.75000000 Z=0.75000000
>
> ATOM 3:X= 0.75000000 Y=0.75000000 Z=0.50000000
>
> ATOM 3:X= 0.75000000 Y=0.50000000 Z=0.75000000
>
> Mn NPT= 781 R0=0.00005000 RMT= 1.9500 Z: 25.0
>
> LOCAL ROT MATRIX: 0.0000000 0.0000000 0.0000000
>
> 0.0000000 0.0000000 0.0000000
>
> 0.0000000 0.0000000 0.0000000
>
> ATOM 4: X=0.26400000 Y=0.26400000 Z=0.26400000
>
> MULT= 8 ISPLIT= 8
>
> ATOM 4:X= 0.73600000 Y=0.73600000 Z=0.73600000
>
> ATOM 4:X= 0.73600000 Y=0.51400000 Z=0.51400000
>
> ATOM 4:X= 0.26400000 Y=0.98600000 Z=0.98600000
>
> ATOM 4:X= 0.98600000 Y=0.98600000 Z=0.26400000
>
> ATOM 4:X= 0.51400000 Y=0.51400000 Z=0.73600000
>
> ATOM 4:X= 0.51400000 Y=0.73600000 Z=0.51400000
>
> ATOM 4:X= 0.98600000 Y=0.26400000 Z=0.98600000
>
> O NPT= 781 R0=0.00010000 RMT= 1.7300 Z: 8.0
>
> LOCAL ROT MATRIX: 0.0000000 0.0000000 0.0000000
>
> 0.0000000 0.0000000 0.0000000
>
> 0.0000000 0.0000000 0.0000000
>
> 0 NUMBER OF SYMMETRY OPERATIONS
>
>
>
> On execution of x sgroup, the following error message occurs:
>
> Error: duplicated atoms found Atom #3 and #9 coincide.
>
>
>
> In another structure file, I have used the following parameters:
>
> Co2MnO4
>
>
> F LATTICE,NONEQUIV.ATOMS:
> 3227_Fd-3m
>
> MODE OF CALC=RELA
> unit=bohr
>
> 15.652608 15.652608 15.652608 90.000000 90.000000
> 90.000000
>
> ATOM -1: X=0.50000000 Y=0.50000000 Z=0.50000000
>
> MULT= 4 ISPLIT= 4
>
> -1: X=0.50000000 Y=0.75000000 Z=0.75000000
>
> -1: X=0.75000000 Y=0.75000000 Z=0.50000000
>
> -1: X=0.75000000 Y=0.50000000 Z=0.75000000
>
> Co2 NPT= 781 R0=0.00005000 RMT= 1.9600 Z: 27.0
>
>
> LOCAL ROT MATRIX: 0.4082483-0.7071068 0.5773503
>
> 0.4082483 0.7071068 0.5773503
>
> -0.8164966 0.0000000 0.5773503
>
> ATOM 2: X=0.12500000 Y=0.12500000 Z=0.12500000
>
> MULT= 2 ISPLIT= 2
>
> 2: X=0.87500000 Y=0.87500000 Z=0.87500000
>
> Mn1 NPT= 781 R0=0.00005000 RMT= 1.9800 Z:
> 25.0
>
> LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
>
> 0.0000000 1.0000000 0.0000000
>
> 0.0000000 0.0000000 1.0000000
>
> ATOM -3: X=0.26370000 Y=0.26370000 Z=0.26370000
>
> MULT= 8 ISPLIT= 4
>
> -3: X=0.73630000 Y=0.73630000 Z=0.73630000
>
> -3: X=0.73630000 Y=0.51370000 Z=0.51370000
>
> -3: X=0.26370000 Y=0.98630000 Z=0.98630000
>
> -3: X=0.98630000 Y=0.98630000 Z=0.26370000
>
> -3: X=0.51370000 Y=0.51370000 Z=0.73630000
>
> -3: X=0.51370000 Y=0.73630000 Z=0.51370000
>
> -3: X=0.98630000 Y=0.26370000 Z=0.98630000
>
> O 4 NPT= 781 R0=0.00010000 RMT= 1.7300 Z: 8.0
>
>
> LOCAL ROT MATRIX: 0.4082483-0.7071068 0.5773503
>
> 0.4082483 0.7071068 0.5773503
>
> -0.8164966 0.0000000 0.5773503
>
> 48 NUMBER OF SYMMETRY OPERATIONS
>
> The other parameters are:
>
> Rmt*Kmax=7, lmax=10, Gmax=12
>
> k points=147
>
> Exchange Correlation Potential- LSDA
>
> Energy to separate core and valance state=-6.0
>
>
>
> Then after executing spin polarized calculation, I got the following
> information about the magnetic moment in case.scf file:
>
> MAGNETIC MOMENTS OF MIXED CHARGE DENSITY
>
> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL = 1.02591
>
> :MMI001: MAGNETIC MOMENT IN SPHERE 1 = 0.28125
>
> :MMI002: MAGNETIC MOMENT IN SPHERE 2 = 3.80049
>
> :MMI003: MAGNETIC MOMENT IN SPHERE 3 = 0.03426
>
> :MMTOT: TOTAL MAGNETIC MOMENT IN CELL = 10.02597
>
>
>
> which seems to be inconsistent.
>
> Please tell me the mistake and suggest accordingly.
>
> With kind regards,
>
> Alpa Dashora
>
>
> ------------------------------------------------------------------------
>
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--
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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