<div dir="ltr">Hi,<div> </div><div>How to activate the ddapc correction? I checked both EXPLICIT_ORBITALS and MAURI_SPZ methods for a charged (+1) box with PBC, the results of the two are exactly the same.</div><div> </div><div>Best,</div><div>Xiaoming Wang On Monday, January 8, 2018 at 11:40:50 AM UTC-5, jgh wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;">Hi yes, I think you are right. This SIC method calculates the electrostatic correction using the same Poisson solver as used for the full density. For PBC this means that the G=0 term is neglected and the SIC correction is calculated using a uniform background charge. The methods in "calc_v_sic_rspace" use a correction, see "cp_ddapc_apply_CD" to avoid this problem. A similar correction would have to be added to the methods in "sic_explicit_orbitals". The following SIC functionals have a PBC correction AD MAURI_SPZ MAURI_US No PBC correction is done for EXPLICIT_ORBITALS (scaled) Perdew-Zunger correction explicitly on a set of orbitals. best Juerg Hutter -------------------------------------------------------------- Juerg Hutter Phone : ++41 44 635 4491 Institut für Chemie C FAX : ++41 44 635 6838 Universität Zürich E-mail: <a href="javascript:" target="_blank" gdf-obfuscated-mailto="k_YBEc_LAAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">hut...@chem.uzh.ch</a> Winterthurerstrasse 190 CH-8057 Zürich, Switzerland --------------------------------------------------------------- -----<a href="javascript:" target="_blank" gdf-obfuscated-mailto="k_YBEc_LAAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a> wrote: ----- To: cp2k <<a href="javascript:" target="_blank" gdf-obfuscated-mailto="k_YBEc_LAAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>> From: Xiaoming Wang Sent by: <a href="javascript:" target="_blank" gdf-obfuscated-mailto="k_YBEc_LAAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a> Date: 01/08/2018 06:23AM Subject: [CP2K:9842] SIC in qs_ks_utils.F Hello, In the lines 613 and 614 of the subroutine qs_ks_utils.F, key operations of the SIC correction are shown: CALL pw_poisson_solve(poisson_env, orb_rho_g%pw, ener, work_v_gspace%pw) energy%hartree = energy%hartree-dft_control%sic_scaling_a*ener The first line calculates the electrostatic energy of the unpaired electron (self-interaction) and the second line subtracts this energy from the total Hartree energy. For open boundary calculations, this is correct, since the electrostatic energy calculated this way is the self-interaction energy. However, for periodic boundary conditions, the electrostatic energy calculated by the first line is not the self-interaction energy. Instead, the interaction energy of the unpaired electron and its periodic images is also included!! (Please correct me if I am wrong.) So it seems that to do a correct SIC calculation for PBC systems, one needs to either add back the interaction energy of the unpaired electron and its periodic images using perhaps Ewald summation method (not sure) or correct the self-interaction term by changing a poisson solver. Is it possible to calculate the Hartree energy using non-periodic poisson solver, say multipole, for a periodic system? Best, Xiaoming -- 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="javascript:" target="_blank" gdf-obfuscated-mailto="k_YBEc_LAAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="k_YBEc_LAAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>. Visit this group at <a href="https://groups.google.com/group/cp2k" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/group/cp2k';return true;" onclick="this.href='https://groups.google.com/group/cp2k';return true;">https://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/d/optout" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/d/optout';return true;" onclick="this.href='https://groups.google.com/d/optout';return true;">https://groups.google.com/d/optout</a>. </blockquote></div></div>