Opposite charges trend as experiment for PdRu Surface Model

Bader charge density analysis

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diana
Posts: 2
Joined: Tue Dec 16, 2014 12:30 am

Opposite charges trend as experiment for PdRu Surface Model

Post by diana »

Hi there!!

I am calculating charges for Pd-Ru Surface Model but unfortunately I managed to get opposite trend as experiment, Pd will donate electron to Ru. I did as instructed in bader website but still, no luck.

I hope you guys here will help me to figure out what was my problem.

this is my poscar:
Pd0.5-Ru0.5_fcc_111_1
1.0
5.5022997856 0.0000000000 0.0000000000
-2.7511498928 4.7651313936 0.0000000000
0.0000000000 0.0000000000 14.8926000595
Pd Ru
6 6
Selective dynamics
Direct
0.001320000 0.993040025 0.316810012 T T T
0.334710002 0.165370002 0.155509993 T T T
0.166669995 0.333330005 0.000000000 F F F
0.501770020 0.994470000 0.308609992 T T T
0.836520016 0.165199995 0.155489996 T T T
0.666670024 0.333330005 0.000000000 F F F
0.001770000 0.494190007 0.318179995 T T T
0.334729999 0.663250029 0.155640006 T T T
0.166669995 0.833329976 0.000000000 F F F
0.501820028 0.494060010 0.318509996 T T T
0.835189998 0.663909972 0.160809994 T T T
0.666670024 0.833329976 0.000000000 F F F

my incar:
#*Basic setup*
SYSTEM = Pd-Ru # name of the system
ISYM = 2 # symmetry: 1,2,3 -on, -1,0 -off

#*Accuracy controls*
ENCUT = 400 # eV

#*Electronic loop controls*
ALGO = Fast # RMM-DIIS
EDIFF = 1.00E-05 # criteria to stop SCF cycle
ISMEAR = 1 # occupancies: -5-Blochl, -4-tet, -1-fermi, 0-gaussian
SIGMA = 0.2 # broadening in eV -4-tet, -1-fermi, 0-gaus for ISMEAR

#*Relaxation control*
IBRION = 2 # -1: no optimization, 0: MD, 1: quasi-Newton, 2: CG, 3: Damped MD
NSW = 100 # max ion steps
ISIF = 2 # calculate stressand what torelax (3-ions=y shape=y volume=y)
EDIFFG = 0.0001 # criteria to stop optimization if positive for energy and negative for force

#*MPI settings*
LPLANE = .TRUE.
NPAR = 4 # parallelization over bands, NPAR = 1when DOS calculation
NSIM = 4 # default = 4
#*functional*
#GGA = PE # for PAW-PBE

LCHARG = .TRUE.
LAECHG = .TRUE.
LWAVE = .FALSE.
LREAL = .FALSE.

and ACF.dat:
# X Y Z CHARGE MIN DIST ATOMIC VOL
--------------------------------------------------------------------------------
1 0.0094 0.0549 4.5166 10.0914 1.2164 48.9382
2 1.3786 0.8169 2.2210 10.0621 1.1836 14.3594
3 0.0000 1.5884 0.0000 10.1573 1.2154 41.3118
4 2.7501 0.0554 4.5159 10.1071 1.2096 48.3467
5 4.1286 0.7309 2.2202 10.0599 1.2060 14.3602
6 2.7512 1.5884 0.0000 10.1608 1.2154 41.4775
7 -1.3715 2.4859 4.2422 7.8093 1.0185 35.0861
8 -0.0863 3.1894 2.1503 7.8684 1.1010 14.2746
9 -1.3755 3.9709 0.0000 8.0026 1.1990 42.1040
10 1.3792 2.5274 4.2138 7.7889 1.0531 34.1834
11 2.8435 3.1889 2.1507 7.9303 1.1478 14.4551
12 1.3756 3.9709 0.0000 7.9621 1.2235 41.5748
--------------------------------------------------------------------------------
VACUUM CHARGE: 0.0000
VACUUM VOLUME: 0.0000
NUMBER OF ELECTRONS: 108.0000


Thank You!
graeme
Site Admin
Posts: 1999
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: Opposite charges trend as experiment for PdRu Surface Mo

Post by graeme »

I don't see a problem with the analysis. There is a very small (~0.1 e, on average) charge transfer from Ru to Pd. This appears consistent with the fact that the two elements have a similar electronegativity.
diana
Posts: 2
Joined: Tue Dec 16, 2014 12:30 am

Re: Opposite charges trend as experiment for PdRu Surface Mo

Post by diana »

Dear Graeme,

Thank You for the reply.

But since my model is Pd-Ru surface (slab) model that imitate the nanoparticle surface, the electronegativity rule seem didn't applied. The experimentalist reported that Pd should donate the electron to Ru, not Ru to Pd. This what made me confused. I am not sure why.

Please....
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