[DFTB-Plus-User] Si20 FPLO-geometry does not SCC-converge

[Vivien Lorenz]

Dear all,

I've been trying to get a certain Si20 cluster converged with DFTB - a 
3-fold symmetric structure as shown on the webpage 
http://altair.physics.ncsu.edu/projects/sismall/siclust.html. I did not 
have the coordinates of the structure, so guessed at them and firstly 
optimized the geometry of the cluster under the given symmetry 
constraints with the DFT code FPLO - no problems there. Now I used the 
resulting atomic position as an input to DFTB, but I do not get the 
charges self-consistently converged.
I have checked all coordinates - they are given in the same units in the 
FPLO as well as in the DFTB output, and they are identical. All other 
DFTB input files already worked for many other calculations. I am 
appending my input files.
Do you have any suggestions for me?

Thanks a lot,
Vivien
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