Dear Naiwrit Karmodak, For these structure type, such as slab or tube, mixing_mode 'plain' is not suitable. Please use 'LOCAL-TF' instead of 'Plain' Also decreasing degauss(0.001) effect the converge in a good way and for better results , the value of conv_thr can be taken 1.0D-8 or less,
kind regards 2015-09-16 6:16 GMT+03:00 Naiwrit Karmodak <[email protected]>: > Hi, > I was trying to relax a nanotube in quantum espresso. But during > optimization the structure is breaking down and unable to converge. I am > giving the input file > &CONTROL > calculation = 'relax' , > restart_mode = 'from_scratch' , > outdir = './' , > pseudo_dir = '/mnt/lustre/ipc2/ipcnwrit/upf_files' , > verbosity = 'low' , > forc_conv_thr = 1.0D-3 > / > &SYSTEM > ibrav = 0, > nat = 12, > ntyp = 1, > ecutwfc = 35, > ecutrho = 270 , > occupations = 'smearing' > smearing = 'gaussian', > degauss = 0.05 > / > &ELECTRONS > conv_thr = 1.0D-6 , > mixing_mode = 'plain' , > diagonalization = 'cg' , > mixing_beta = 0.55 > / > &IONS > ion_dynamics = 'bfgs' , > / > CELL_PARAMETERS > 14.0 0.0 0.0 > 0.0 14.0 0.0 > 0.0 0.0 2.47 > ATOMIC_SPECIES > C 12.01000 C.pbe-rrkjus.UPF > ATOMIC_POSITIONS > C 0.0863 0.1169 0.0443 > C 0.9137 0.8831 0.1321 > C 0.9910 0.1450 0.0443 > C 0.0090 0.8550 0.1321 > C 0.8556 0.0163 0.0443 > C 0.1444 0.9837 0.1321 > C 0.8789 0.9197 0.0443 > C 0.1211 0.0803 0.1321 > C 0.0581 0.8668 0.0443 > C 0.9419 0.1332 0.1321 > C 0.1301 0.9353 0.0443 > C 0.8699 0.0647 0.1321 > > K_POINTS automatic > 1 1 10 1 1 1 > > This is a 3,3 nanotube. I have also tried with 6,6 nanotube and the > problem is same. Both david and cg option for diagonalization is not giving > any way to optimized geometry. Please suggest a solution for this. > > -- > > Naiwrit Karmodak > Research Scholar, > C/o Prof E. D. Jemmis. > Inorganic and Physical Chemistry, > Indian Institute of Science, Bangalore-560012 > > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- Bahadır SALMANKURT Sakarya University, TURKEY Ph.D. student of Physics
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