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