Is it good enough to relax an arbitrary system with only gamma k-points? I thought it is necessary to do some test with k-points as this effect change from system to system. In my experience, more k-points is necessary for a metal-like system, i.e. graphene.
Best regards, Wu, F > Date: Thu, 8 Sep 2011 11:12:24 -0400 > From: xijunw at gmail.com > To: pw_forum at pwscf.org > Subject: Re: [Pw_forum] problems with vc-relax > > On Thu, Sep 8, 2011 at 10:26 AM, Elie Moujaes > <elie.moujaes at hotmail.co.uk> wrote: > > Hello Xijun, > > Hello Elie, > > > I did not send the e-mail twice intentionally. There was a problem with my > > e-mail and it kept giving me an error about problems with Windows hotmai > > hence why it was sent twice without me knowing except now when I opened my > > e-mail so I apologize for that. Also I wont include blank lines in the input > > file either. Back to my calculations, I have restarted the calculations, it > > went fine at first but then I got the error: > > from scale_h: not enough memory allocated for radial FFT; try restarting > > with a larger cell_factor. > > Check the manual for definition of cell_factor. The default value is > 1.2, you could try a larger value. > > What's your new K_POINTS setting? Since you are relax the system, I > suggest you start from: > > K_POINTS {gamma} > > This will far faster. and need far less memory. > > > Another simple question: I realized when I restarted everything that the > > positions of the atoms were the initial ones even before starting the > > relaxation process where as the k-points used were the NEW ones. Is that > > normal? or should I have substituted the the C atoms positions by the most > > recent ones then restart again? > > Yes, restart again with NEW ATOMIC_POSITIONS and "restart_mode= 'from_scratch' " > > Regards, > - Xijun > > > Regards > > Elie > > > >> Date: Wed, 7 Sep 2011 16:20:49 -0400 > >> From: xijunw at gmail.com > >> To: pw_forum at pwscf.org > >> Subject: Re: [Pw_forum] problems with vc-relax > >> > >> Hi, Elie, > >> > >> Please do not repeat sending the same message to the mail list. Also, > >> people will be more happy to help you if you keep your mail neat by > >> removing all the unnecessary blank lines in the input file. > >> > >> Regards, > >> Xijun > >> > >> On Wed, Sep 7, 2011 at 3:28 PM, Elie Moujaes <elie.moujaes at hotmail.co.uk> > >> wrote: > >> > Dear all, > >> > > >> > > >> > > >> > I am relaxing a 60 atom supercell (graphene grain boundary) to make the > >> > total force on atoms mainly 0.001 Ry/au. However the vc-relax stopped > >> > after > >> > 4 days of execution and without reaching the desired force threshold. > >> > The > >> > following output was obtained : > >> > > >> > > >> > > >> > 1st relaxation process: > >> > > >> > > >> > > >> > Total force 0.091 Pressure =- 114.1 kbar > >> > > >> > > >> > > >> > 2nd relaxation process: > >> > > >> > > >> > > >> > total force 0.1 Pressure = -55 kbar > >> > > >> > > >> > > >> > (new enthalpy < old enthalpy) > >> > > >> > > >> > > >> > 3rd process: > >> > > >> > > >> > > >> > total force = 0.058 pressure = -11 kbar > >> > > >> > > >> > > >> > Then in the 4th process, calculations stopped. Here are the last few > >> > lines > >> > of the output: > >> > > >> > > >> > > >> > iteration # 2 ecut= 36.75 Ry beta=0.30 > >> > Davidson diagonalization with overlap > >> > c_bands: 5 eigenvalues not converged > >> > c_bands: 1 eigenvalues not converged > >> > c_bands: 3 eigenvalues not converged > >> > c_bands: 1 eigenvalues not converged > >> > c_bands: 4 eigenvalues not converged > >> > c_bands: 4 eigenvalues not converged > >> > c_bands: 4 eigenvalues not converged > >> > c_bands: 4 eigenvalues not converged > >> > c_bands: 5 eigenvalues not converged > >> > c_bands: 5 eigenvalues not converged > >> > c_bands: 2 eigenvalues not converged > >> > c_bands: 2 eigenvalues not converged > >> > ethr = 2.90E-04, avg # of iterations = 17.6 > >> > > >> > negative rho (up, down): 0.132E-01 0.000E+00 > >> > > >> > total cpu time spent up to now is 382283.13 secs > >> > > >> > total energy = -676.77947904 Ry > >> > Harris-Foulkes estimate = -676.82846513 Ry > >> > estimated scf accuracy < 0.17363554 Ry > >> > > >> > iteration # 3 ecut= 36.75 Ry beta=0.30 > >> > Davidson diagonalization with overlap > >> > c_bands: 1 eigenvalues not converged > >> > c_bands: 1 eigenvalues not converged > >> > c_bands: 2 eigenvalues not converged > >> > c_bands: 3 eigenvalues not converged > >> > > >> > > >> > > >> > The input of the vc-relax is: > >> > > >> > > >> > > >> > &control > >> > > >> > prefix='GBphonon', > >> > > >> > calculation='vc-relax', > >> > > >> > restart_mode='from_scratch', > >> > > >> > tstress=.true., > >> > > >> > tprnfor=.true, > >> > > >> > pseudo_dir = > >> > '/exp/home/caiapo/emoujaes/espresso/espresso-4.3/Pseudo/', > >> > > >> > outdir='/exp/home/caiapo/emoujaes/espresso/Moujaes-Results/', > >> > > >> > > >> > > >> > / > >> > > >> > &system > >> > > >> > ibrav= 0, celldm(1) =1.889725989, nat=60, ntyp= 1, ecutwfc > >> > =36.749309, > >> > occupations='smearing', smearing='mp',degauss=0.01 > >> > > >> > / > >> > > >> > &electrons > >> > > >> > conv_thr=1.D-6, > >> > > >> > mixing_beta=0.3D0, > >> > > >> > diago_david_ndim=2, > >> > > >> > > >> > > >> > / > >> > > >> > > >> > > >> > &ions > >> > > >> > ion_dynamics='bfgs' > >> > > >> > > >> > > >> > / > >> > > >> > $cell > >> > > >> > cell_dynamics='bfgs', > >> > > >> > > >> > > >> > / > >> > > >> > > >> > > >> > CELL_PARAMETERS (alat) > >> > > >> > 24.064488464 0.000772242 0.000000000 > >> > > >> > 0.000000000 6.503051170 0.000000000 > >> > > >> > 0.000000000 0.000000000 8.470514812 > >> > > >> > > >> > > >> > > >> > > >> > ATOMIC_SPECIES > >> > > >> > C 12.0107 C.blyp-mt.UPF > >> > > >> > > >> > > >> > ATOMIC_POSITIONS (angstrom) > >> > > >> > C -11.330758616 -3.527803203 0.000000000 > >> > > >> > C -10.659793092 -1.160339161 0.000000000 > >> > > >> > C -12.039843315 -7.112619698 0.000000000 > >> > > >> > C -12.041158182 -5.732701936 0.000000000 > >> > > >> > C -10.941089654 -4.881442842 0.000000000 > >> > > >> > ...... > >> > > >> > > >> > > >> > Please can anyone advice me on this? Shall I start with the new > >> > configuration and start relaxing again? > >> > > >> > > >> > > >> > Regards > >> > > >> > > >> > > >> > Elie Moujaes > >> > > >> > University of Nott > >> > > >> > University Park > >> > > >> > NGT 3RD > >> > > >> > > >> > > >> > _______________________________________________ > >> > Pw_forum mailing list > >> > Pw_forum at pwscf.org > >> > http://www.democritos.it/mailman/listinfo/pw_forum > >> > > >> > > >> > >> > >> > >> -- > >> Dept. of Chem and Biochem, Concordia University > >> 7141 Sherbrooke Ouest, Montreal, QC, Canada (H4B 1R6) > >> Tel: 514-848-2424-#5835 (Lab) TA office: SP175.23 > >> _______________________________________________ > >> Pw_forum mailing list > >> Pw_forum at pwscf.org > >> http://www.democritos.it/mailman/listinfo/pw_forum > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > > -- > Dept. of Chem and Biochem, Concordia University > 7141 Sherbrooke Ouest, Montreal, QC, Canada (H4B 1R6) > Tel: 514-848-2424-#5835 (Lab) TA office: SP175.23 > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum ----------------------------------------------------------- Wu, F College of Chemistry and Molecular Engineering, Peking University ----------------------------------------------------------