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</o:shapelayout></xml><![endif]--></head><body lang=ZH-CN link=blue vlink=purple style='text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hello everyone,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> I am calculating a surface slab model of MoS2. My parameter works well with 5~11 layers. But with 13 layers ( 39 atoms total ), it gives<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> from good_fft_order : error # 2241<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> fft order too large<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Decreasing Ecutwfc/Ecutrho can eliminate these problem. But these Ecutwfc/Ecutrho is determined by convergence test of bulk lattice parameter test, so I would like to find a way to solve this problem without decreasing Ecutwfc/Ecutrho. Is there any suggestion ?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>My input file is like this: ( all 5~11layers input files are just same except atoms related part )<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>======================================<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>&control<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> calculation = 'relax'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> restart_mode = 'from_scratch'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> tstress = .true.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> tprnfor = .true.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> outdir = './out'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> wfcdir = './wfc' <o:p></o:p></span></p><p class=MsoNormal style='text-indent:10.5pt'><span lang=EN-US>prefix = 'MoS2'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>/<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>&system<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ntyp = 2<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> nat = 39<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ibrav = 4<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> celldm(1) = 6.108157<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> celldm(3) = 40.745230<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ecutwfc = 100.0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ecutrho = 800.0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> london = .false.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>/<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>&electrons<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> diagonalization = 'cg'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> mixing_mode = 'plain'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> mixing_beta = 0.7<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> conv_thr = 1.00d-08<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>/<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>&ions<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ion_dynamics = 'bfgs'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> ion_positions = 'default'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>/<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>ATOMIC_SPECIES<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>S 32.070000 S.vdwDF-tmus-tmc.UPF<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Mo 95.940000 Mo.vdwDF-rrkjus-tmc.UPF<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>(Atomic position is negelected for it is too long)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>K_POINTS automatic<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>8 8 1 1 1 1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>=====================================<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Best Regards,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>F, Wu<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>-----------------------------------------------------------<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>F, Wu<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>College of Chemistry and Molecular Engineering Peking University<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>----------------------------------------------------------<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></body></html>