[Pw_forum] The scf calculation is not converged

[vega]

Dear all,

First I relaxed a multi-layer structure, something like rutile 110 oriented ultra-thin film illustrated in Phys. Rev. B 2004, 70 (3) (http://prola.aps.org/abstract/PRB/v70/i3/e035419). I want to calculate the binding energy between different layers. So I divided the slab into two parts, up and down. The dimension of  the box was remaining the same as the whole relaxed layer slab.  the only difference was the number of atoms in the box. some box missing upper part of slab and some down. And then I did a scf calculation for each one. But some scf calculations can't be  converged  even in 1000 cycles. Also many other scf calculation can be converged in about 30 cycles. How could I deal with the convergence problem?

thank you for reading

vega  

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Vega Lew (weijia liu)
PH.D Candidate in Chemical Engineering
State Key Laboratory of Materials-oriented Chemical Engineering
College of Chemistry and Chemical Engineering
Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
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