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I'm trying to get correct Bader charges for Ge-Ge dimers on Ge(2x1) surface reconstruction. The slab has 2 identical (2x1) surfaces with 4 dimers per surface. The slab has 64 atoms (with no H passivation). If Ge bulk atom has Bader charge 4, the upper atom in the dimer should have Bader charge around 5 and lower atom in the dimer should have Bader charge around 3. I persistently get different values: upper Ge atom in the dimer has charge around 3.92 |e| and lower Ge atom in the dimer has charge around 3.96 |e|. Values look wrong and relation between upper and lower atom charges looks wrong. Below is one of my INCAR files. In fact, I repeated this simulation with various parameters: a) spin polarized and no-spin; b) various PP's: Ge, Ge_d, Ge_h; c) PREC=Medium and PREC=High; d) KPOINTS were GAMMA 3x3x1 and GAMMA 7x7x1 e) with Bader core correction and without it; f) ISMEAR=0 and ISMEAR=-5. All these simulations returned similar values which look wrong. Please let me know if you know how to fix it. To get Bader charges utility from UT Texas was used. Thank you.

# SYSTEM NAME
SYSTEM = Ge 2x1 reconstruction
# OUTPUT AND START
NWRITE=2
ISTART=1
# ELECTRONIC CONVERGENCE
NELM=100
ISMEAR=0
SIGMA=0.2
EDIFF=1E-6
PREC=High
LREAL=Auto
# TYPE OF RUN
IBRION=-1
NSW=0
LAECHG=.TRUE.
# SPIN AND FUNCTIONAL
ISPIN=2
GGA=PE

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