<div dir="ltr">Hello everyone,<div><br></div><div>I seem to have stumbled on something. I noticed some funny scaling (or rather, a lack of scaling) when performing AIMD simulations with DFT-D3. I've tracked the problem to the calculation of the C9 term, when I have that set to be calculated the simulation doesn't scale at all and it takes a long time versus when I have it set to not be calculated, in which case I do get linear scaling. Below is a timing report for the same exact INPUT file, with the only difference being the calculation of the C9 term being set to T and F, respectively. Something interesting is how different they are. Again, these are from the exact same INPUT file, with the exact same number of processors, and the only difference is the CALCULATE_C9_TERM is set to T in the first case and F in the second. </div><div><br></div><div>timing with C9 calculation:</div><div><br></div><div><div><font face="courier new, monospace"> -------------------------------------------------------------------------------</font></div><div><font face="courier new, monospace"> - -</font></div><div><font face="courier new, monospace"> - T I M I N G -</font></div><div><font face="courier new, monospace"> - -</font></div><div><font face="courier new, monospace"> -------------------------------------------------------------------------------</font></div><div><font face="courier new, monospace"> SUBROUTINE CALLS ASD SELF TIME TOTAL TIME</font></div><div><font face="courier new, monospace"> MAXIMUM AVERAGE MAXIMUM AVERAGE MAXIMUM</font></div><div><font face="courier new, monospace"> CP2K 1 1.0 0.008 0.019 772.815 772.821</font></div><div><font face="courier new, monospace"> qs_mol_dyn_low 1 2.0 0.002 0.003 772.503 772.517</font></div><div><font face="courier new, monospace"> qs_forces 11 3.9 0.002 0.002 771.252 771.258</font></div><div><font face="courier new, monospace"> qs_energies 11 4.9 0.001 0.001 765.300 765.307</font></div><div><font face="courier new, monospace"> velocity_verlet 10 3.0 0.002 0.002 686.306 686.323</font></div><div><font face="courier new, monospace"> qs_energies_init_hamiltonians 11 5.9 0.000 0.000 686.298 686.303</font></div><div><font face="courier new, monospace"> mp_sum_d 4362 11.6 619.789 685.783 619.789 685.783</font></div><div><font face="courier new, monospace"> calculate_dispersion_pairpot 11 6.9 65.911 685.372 685.486 685.491</font></div><div><font face="courier new, monospace"> scf_env_do_scf 11 5.9 0.000 0.001 76.654 76.655</font></div><div><font face="courier new, monospace"> scf_env_do_scf_inner_loop 139 6.7 0.004 0.030 71.107 71.468</font></div><div><font face="courier new, monospace"> rebuild_ks_matrix 150 8.5 0.000 0.001 52.308 52.341</font></div><div><font face="courier new, monospace"> qs_ks_build_kohn_sham_matrix 150 9.5 0.017 0.021 52.307 52.340</font></div><div><font face="courier new, monospace"> qs_ks_update_qs_env 151 7.7 0.001 0.001 47.661 47.693</font></div><div><font face="courier new, monospace"> pw_transfer 4061 12.2 0.239 0.267 35.026 35.154</font></div><div><font face="courier new, monospace"> fft_wrap_pw1pw2 3761 13.2 0.028 0.031 34.447 34.575</font></div><div><font face="courier new, monospace"> fft_wrap_pw1pw2_350 1661 14.3 2.499 2.594 32.640 32.789</font></div><div><font face="courier new, monospace"> qs_vxc_create 150 10.5 0.003 0.004 30.531 30.553</font></div><div><font face="courier new, monospace"> xc_vxc_pw_create 150 11.5 1.027 1.065 30.528 30.551</font></div><div><font face="courier new, monospace"> fft3d_ps 3761 15.2 12.507 12.766 28.236 28.478</font></div><div><font face="courier new, monospace"> qs_rho_update_rho 150 7.8 0.001 0.001 18.349 18.356</font></div><div><font face="courier new, monospace"> calculate_rho_elec 150 8.8 3.941 4.247 18.348 18.355</font></div><div><font face="courier new, monospace"> xc_rho_set_and_dset_create 150 12.5 0.188 0.193 16.380 16.402</font></div><div><font face="courier new, monospace"> sum_up_and_integrate 150 10.5 0.079 0.082 15.635 15.650</font></div><div><font face="courier new, monospace"> integrate_v_rspace 150 11.5 4.076 4.275 15.556 15.572</font></div><div><font face="courier new, monospace"> -------------------------------------------------------------------------------</font></div></div><div><font face="arial, sans-serif"><br></font></div><div><font face="arial, sans-serif">Without c9 calculation </font></div><div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace"><div> -------------------------------------------------------------------------------</div><div> - -</div><div> - T I M I N G -</div><div> - -</div><div> -------------------------------------------------------------------------------</div><div> SUBROUTINE CALLS ASD SELF TIME TOTAL TIME</div><div> MAXIMUM AVERAGE MAXIMUM AVERAGE MAXIMUM</div><div> CP2K 1 1.0 0.010 0.023 98.369 98.371</div><div> qs_mol_dyn_low 1 2.0 0.002 0.003 98.009 98.019</div><div> qs_forces 11 3.9 0.002 0.002 97.695 97.697</div><div> qs_energies 11 4.9 0.001 0.001 91.392 91.395</div><div> scf_env_do_scf 11 5.9 0.000 0.001 84.901 84.903</div><div> scf_env_do_scf_inner_loop 139 6.7 0.004 0.028 78.845 79.075</div><div> velocity_verlet 10 3.0 0.002 0.002 67.867 67.871</div><div> rebuild_ks_matrix 150 8.5 0.000 0.001 55.485 55.544</div><div> qs_ks_build_kohn_sham_matrix 150 9.5 0.017 0.020 55.484 55.543</div><div> qs_ks_update_qs_env 151 7.7 0.001 0.001 50.557 50.612</div><div> pw_transfer 3461 12.2 0.206 0.259 37.722 37.838</div><div> fft_wrap_pw1pw2 3161 13.2 0.027 0.033 37.180 37.297</div><div> fft_wrap_pw1pw2_350 1661 14.3 2.439 2.559 34.568 34.695</div><div> qs_vxc_create 150 10.5 0.003 0.004 31.774 31.801</div><div> xc_vxc_pw_create 150 11.5 1.015 1.048 31.771 31.798</div><div> fft3d_ps 3161 15.2 12.404 12.688 31.074 31.311</div><div> qs_rho_update_rho 150 7.8 0.001 0.001 20.139 20.150</div><div> calculate_rho_elec 150 8.8 3.909 4.230 20.138 20.149</div><div> sum_up_and_integrate 150 10.5 0.077 0.081 17.172 17.191</div><div> integrate_v_rspace 150 11.5 4.070 4.271 17.094 17.111</div><div> xc_rho_set_and_dset_create 150 12.5 0.185 0.190 16.948 16.973</div><div> rs_pw_transfer 1822 12.1 0.020 0.024 15.129 15.437</div><div> mp_alltoall_z22v 3161 17.2 15.000 15.294 15.000 15.294</div><div> density_rs2pw 150 9.8 0.007 0.009 14.718 14.977</div><div> qs_scf_new_mos 139 7.7 0.001 0.001 14.120 14.173</div><div> qs_scf_loop_do_ot 139 8.7 0.001 0.001 14.120 14.173</div><div> dbcsr_multiply_generic 2770 12.6 0.073 0.082 13.810 13.940</div><div> ot_scf_mini 139 9.7 0.005 0.006 13.225 13.279</div><div> potential_pw2rs 150 12.5 0.010 0.013 12.324 12.362</div><div> x_to_yz 1050 16.5 1.546 1.618 9.447 9.550</div><div> multiply_cannon 2770 13.6 0.293 0.307 8.197 8.790</div><div> yz_to_x 911 16.0 1.073 1.104 8.140 8.355</div><div> mp_waitall_1 427928 15.4 7.704 8.344 7.704 8.344</div><div> ot_mini 139 10.7 0.001 0.001 8.062 8.132</div><div> qs_ot_get_derivative 139 11.7 0.002 0.002 6.714 6.768</div><div> xc_functional_eval 150 13.5 0.002 0.004 6.023 6.043</div><div> pbe_lda_eval 150 14.5 6.021 6.041 6.021 6.041</div><div> init_scf_loop 12 6.8 0.000 0.000 5.780 5.780</div><div> qs_ks_update_qs_env_forces 11 4.9 0.000 0.000 4.981 4.985</div><div> rs_pw_transfer_PW2RS_350 161 14.2 2.271 2.444 4.256 4.435</div><div> mp_waitany 18660 14.0 3.701 4.433 3.701 4.433</div><div> make_m2s 5540 13.6 0.087 0.097 4.247 4.358</div><div> rs_pw_transfer_RS2PW_350 161 11.6 2.137 2.399 3.706 3.947</div><div> make_images 5540 14.6 0.322 0.341 3.720 3.811</div><div> qs_ot_get_derivative_taylor 110 12.9 0.003 0.004 3.646 3.691</div><div> qs_energies_init_hamiltonians 11 5.9 0.000 0.000 3.259 3.259</div><div> multiply_cannon_multrec 33240 14.6 2.695 3.049 2.705 3.060</div><div> qs_ot_get_p 151 10.5 0.001 0.001 2.871 2.945</div><div> init_scf_run 11 5.9 0.000 0.001 2.925 2.925</div><div> scf_env_initial_rho_setup 11 6.9 0.000 0.000 2.925 2.925</div><div><div> multiply_cannon_metrocomm1 33240 14.6 0.049 0.053 2.285 2.914</div><div> multiply_cannon_metrocomm3 33240 14.6 0.040 0.045 0.735 2.682</div><div> mp_sum_d 4362 11.6 2.357 2.664 2.357 2.664</div><div> wfi_extrapolate 11 7.9 0.000 0.001 2.650 2.650</div><div> calculate_dispersion_pairpot 11 6.9 0.219 2.076 2.327 2.327</div><div> make_images_sizes 5540 15.6 0.006 0.007 1.394 1.992</div><div> mp_alltoall_i44 5540 16.6 1.388 1.986 1.388 1.986</div><div> -------------------------------------------------------------------------------</div></div><div><br></div></font></div><div><font face="courier new, monospace"><br></font></div><div><br></div></div>