[Wien] error : ifft too small in xcpot3

[Peter Blaha]

Increase the 1.00 "enhancement factor" in case.in0  to eg. 1.3

Am 07.11.2012 06:27, schrieb Mojtaba Zareii:
> Dear Wien2k users
> I wanted to study the electronic structure of LaNi5H7 compound. I used
> the experimental lattice constants and Wyckoff positions as start
> point. To get the optimized lattice parameters, I set Rmt equal to
> 2.35, 1.8 and 0.9 (in a.u.) for La, Ni and H atoms, respectively. The
> RmtKmat value of 4.5 was also chosen by energy convergence criterion.
> Gmax was set to 18.
> I run the optimization program by option [1], i.e. “VARY VOLUME with
> CONSTANT RATIO A: B: C”
> With volume variations of +9, +6, +3, 0, -3, -6, -9 %.
> The optimization program run successfully for volume variations of +3,
> 0, -3, -6, -9 %, but it was stopped , in the first itineration of +6%
> volume, with the following error:
> Error in LAPW0
>   'SETFF1' - ifft too small in xcpot3
>   'SETFF1' - 2*(KKK+1) LARGER THAN IFFT PARAMETERS IN XCPOT3
>   'SETFF1' - KKK=  30 -15   0
>   'SETFF1' - IIx=  30 -15   0
>   'SETFF1' - IFFT=  60  60  96
>
> As suggested in UG, one should increase IFFT factor for system
> containing H atoms. So I find “case.ino” file as follows:
> ------------------------ case. In0 -----------
> TOT   13    (5...CA-LDA, 13...PBE-GGA, 11...WC-GGA)
> NR2V      IFFT      (R2V)
>    60  60  96    1.00  1    min IFFT-parameters, enhancement factor, iprint
> ---------------------------------------
> It seems that IFFT was automatically set equal to 1 by program.
> Now, I don’t know how to edit “case.in0” file and choose a proper IFFT factor?
> Should I also change IFFTx,y,z ? What are the proper values for them?
>
>
> Thank you
> S.M.Zareii
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-- 
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Peter Blaha
Inst. Materials Chemistry, TU Vienna
Getreidemarkt 9, A-1060 Vienna, Austria
Tel: +43-1-5880115671
Fax: +43-1-5880115698
email: pblaha at theochem.tuwien.ac.at
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