<div dir="ltr"><div><div><div>Dear brhr, </div> Adding to Jürg's answer, if I remember correctly in VASP the total energy of the pseudo atoms (stored in the POTCAR files) is subtracted from the total energy. So even if you could (you most likely cannot, the kind of pseudo potentials is limited in both codes) calculate the total energy with a consistent set of the other parametres, you should consider also the energy of the isolated (spherical) atoms. </div> Greetings from Paris, </div> apsi </div><div class="gmail_extra"> <div class="gmail_quote">2018-02-21 12:30 GMT+01:00 <<a href="mailto:hut...@chem.uzh.ch" target="_blank">hut...@chem.uzh.ch</a>>: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi in descending order: - pseudopotentials - k-points - basis sets only if you would have all of this equal, you could have the same results. For comparing total energies with VASP you need to converge a VASP PAW result wrt cutoff and k-points and then do a CP2K GAPW all-electron calculation with the same k-point grid and with a converged basis set. With these settings total energies could be rather close. regards Juerg Hutter -------------------------------------------------------------- Juerg Hutter Phone : <a href="tel:%2B%2B41%2044%20635%204491" value="+41446354491">++41 44 635 4491</a> Institut für Chemie C FAX : <a href="tel:%2B%2B41%2044%20635%206838" value="+41446356838">++41 44 635 6838</a> Universität Zürich E-mail: <a href="mailto:hut...@chem.uzh.ch">hut...@chem.uzh.ch</a> Winterthurerstrasse 190 CH-8057 Zürich, Switzerland --------------------------------------------------------------- -----<a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> wrote: -----To: cp2k <<a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>> From: brhr Sent by: <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> Date: 02/21/2018 12:16PM Subject: [CP2K:10014] Energy difference between CP2K and VASP energy calculation results of fcc Si <div class="HOEnZb"><div class="h5"> Dear CP2K experts, I have a very rudimental (probably stupid) question..... Energy of face centered cubic Si which calculated by VASP found at VASPwiki example page (<a href="https://cms.mpi.univie.ac.at/wiki/index.php/Fcc_Si" rel="noreferrer" target="_blank">https://cms.mpi.univie.ac.at/wiki/index.php/Fcc_Si</a>) is -4.8758538 eV when the lattice parameter is 3.9 angstrom. I also found fcc Si calculations at the CP2K tutorial pages. ( "Simple Static Energy and Force Calculation Using QUICKSTEP"(<a href="http://www.cp2k.org/tutorials:static_calculation" rel="noreferrer" target="_blank">http://www.cp2k.org/tutorials:static_calculation</a>) and "How To Converge The Multi-Grid Used in QUICKSTEP"(<a href="http://www.cp2k.org/tutorials:converging_grid" rel="noreferrer" target="_blank">http://www.cp2k.org/tutorials:converging_grid</a>) ) Energy cutoff values, lattice parameters and XC functional are different between these VASP and CP2K cases, and SCF_MAX is set to 1 in the case of CP2K. So I calculated fcc Si energy with CP2K 5.1 setting the energy cutoff 240 eV ~ 8.820 a.u., the lattice parameter 3.9 angstrom, XC functional PBE and SCF_MAX defaut value. The input file is the following: ----------------------------------------------------------------- @SET twice_lp 7.80&GLOBAL PROJECT Si_bulk8 RUN_TYPE ENERGY PRINT_LEVEL MEDIUM &END GLOBAL &FORCE_EVAL METHOD Quickstep &DFT BASIS_SET_FILE_NAME BASIS_SET POTENTIAL_FILE_NAME GTH_POTENTIALS &MGRID CUTOFF 8.820 &END MGRID &QS EPS_DEFAULT 1.0E-10 &END QS &SCF SCF_GUESS ATOMIC EPS_SCF 1.0E-6 ADDED_MOS 10 CHOLESKY INVERSE &SMEAR ON METHOD FERMI_DIRAC ELECTRONIC_TEMPERATURE [K] 300 &END SMEAR &DIAGONALIZATION ALGORITHM STANDARD &END DIAGONALIZATION &MIXING METHOD BROYDEN_MIXING ALPHA 0.4 BETA 0.5 NBROYDEN 8 &END MIXING &END SCF &XC &XC_FUNCTIONAL PBE &END XC_FUNCTIONAL &END XC &END DFT &SUBSYS &KIND Si ELEMENT Si BASIS_SET DZVP-GTH-PBE POTENTIAL GTH-PBE-q4 &END KIND &CELL SYMMETRY CUBIC A ${twice_lp} 0.00 0.00 B 0.00 ${twice_lp} 0.00 C 0.00 0.00 ${twice_lp} &END CELL &COORD SCALED Si 0.00 0.00 0.00 Si 0.00 0.50 0.50 Si 0.50 0.50 0.00 Si 0.50 0.00 0.50 Si 0.75 0.25 0.75 Si 0.25 0.25 0.25 Si 0.25 0.75 0.75 Si 0.75 0.75 0.25 &END COORD &END SUBSYS &PRINT &TOTAL_NUMBERS ON &END TOTAL_NUMBERS &END PRINT &END FORCE_EVAL----------------------------------------------------------------- A part of the result by CP2K 5.1 is ----------------------------------------------------------------- SCF WAVEFUNCTION OPTIMIZATION Step Update method Time Convergence Total energy Change ------------------------------------------------------------------------------ 1 NoMix/Diag. 0.40E+00 0.2 3.06132393 -28.5675142867 -2.86E+01 2 Broy./Diag. 0.40E+00 0.3 2.32214549 -28.7998050659 -2.32E-01 3 Broy./Diag. 0.40E+00 0.3 0.58522732 -29.4698863750 -6.70E-01 4 Broy./Diag. 0.40E+00 0.3 0.20998859 -29.2828168394 1.87E-01 5 Broy./Diag. 0.40E+00 0.3 0.12057075 -29.1932153866 8.96E-02 6 Broy./Diag. 0.40E+00 0.3 0.05618396 -29.1361561613 5.71E-02 7 Broy./Diag. 0.40E+00 0.3 0.01016729 -29.1363881842 -2.32E-04 8 Broy./Diag. 0.40E+00 0.3 0.00251115 -29.1338276656 2.56E-03 9 Broy./Diag. 0.40E+00 0.3 0.00053053 -29.1364584302 -2.63E-03 10 Broy./Diag. 0.40E+00 0.3 0.00012439 -29.1370164369 -5.58E-04 11 Broy./Diag. 0.40E+00 0.3 0.00008751 -29.1372252303 -2.09E-04 12 Broy./Diag. 0.40E+00 0.3 0.00001301 -29.1371970535 2.82E-05 13 Broy./Diag. 0.40E+00 0.3 0.00001000 -29.1371543754 4.27E-05 14 Broy./Diag. 0.40E+00 0.3 0.00000033 -29.1371468686 7.51E-06 *** SCF run converged in 14 steps *** Electronic density on regular grids: -32.0116716966 -0.0116716966 Core density on regular grids: 32.0008931651 0.0008931651 Total charge density on r-space grids: -0.0107785315 Total charge density g-space grids: -0.0107785315 Overlap energy of the core charge distribution: 0.00000000000000 Self energy of the core charge distribution: -82.06393942512820 Core Hamiltonian energy: 15.15717724613789 Hartree energy: 46.02547467061829 Exchange-correlation energy: -8.25223104355429 Electronic entropic energy: -0.00362831666283 Fermi energy: -0.03620657710631 Total energy: -29.13714686858875----------------------------------------------------------------- The obtained energy per atom is -29.13714686858875 / 8 = -3.64214335857359375 a.u. ~ -99.10776 eV This is very different from -4.8758538 eV. Could anyone interpret the difference between these results? Thank you in advance. brhr -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k%2Bun...@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. Visit this group at <a href="https://groups.google.com/group/cp2k" rel="noreferrer" target="_blank">https://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/d/optout" rel="noreferrer" target="_blank">https://groups.google.com/d/optout</a>. -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k%2Bun...@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. Visit this group at <a href="https://groups.google.com/group/cp2k" rel="noreferrer" target="_blank">https://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/d/optout" rel="noreferrer" target="_blank">https://groups.google.com/d/optout</a>. </div></div></blockquote></div> -- <div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=- Ari Paavo Seitsonen / <a href="mailto:Ari.P.S...@iki.fi" target="_blank">Ari.P.S...@iki.fi</a> / <a href="http://www.iki.fi/~apsi/" target="_blank">http://www.iki.fi/~apsi/</a> Ecole Normale Supérieure (ENS), Département de Chimie, Paris Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935 </div></div></div></div></div></div> </div>