Dear Mathias, I have read the excellent paper you provided, in which it states: "<span style="color: rgb(15, 15, 15); font-family: Söhne, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, Cantarell, "Noto Sans", sans-serif, "Helvetica Neue", Arial, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"; font-size: 16px; white-space-collapse: preserve;">The simulations were performed with a multiplicity (2S + 1)Fe2+ = 5 for systems with a ferrous iron and (2S + 1)Fe3+ = 6 for systems with a ferric iron, respectively." Should I set the MULTIPLICITY in cp2k to 5 for FeO system? Does MULTIPLICITY have a noticeable influence on the EOS curve? Btw, could you please help to explain how to calucalte the MULTIPLICITY for Fe2+ or Fe3+? I got the following results from ChatGPT, which differs from yours. <ol style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; list-style: none; margin: 1.25em 0px; padding: 0px; counter-reset: list-number 0; display: flex; flex-direction: column; font-family: Söhne, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, Cantarell, "Noto Sans", sans-serif, "Helvetica Neue", Arial, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"; font-size: 16px; white-space-collapse: preserve;"><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin-bottom: 0px; margin-top: 0px; padding-left: 0.375em; counter-increment: list-number 1; display: block; min-height: 28px;">Fe²⁺ (Iron(II) Ion): Loses two electrons.<ul style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; list-style: disc; margin: 0px 0px 0px 1rem; padding: 0px; display: flex; flex-direction: column;"><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Electron configuration: <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">[Ar]3d6</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">There are 6 electrons in the 3d orbital. According to Hund's rule, the maximum multiplicity arises when the electrons are unpaired as much as possible. The 3d orbital can hold up to 10 electrons, so with 6 electrons, 4 of them can be paired, and 2 are unpaired.</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Total spin <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">S is the number of unpaired electrons divided by 2, which is <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">2/2=1.</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Multiplicity = <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">2S+1=2×1+1=3.</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Therefore, the multiplicity for Fe²⁺ is 3.</li></ul></li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin-bottom: 0px; margin-top: 0px; padding-left: 0.375em; counter-increment: list-number 1; display: block; min-height: 28px;">Fe³⁺ (Iron(III) Ion): Loses three electrons.<ul style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; list-style: disc; margin: 0px 0px 0px 1rem; padding: 0px; display: flex; flex-direction: column;"><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Electron configuration: <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">[Ar]3d5</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">There are 5 electrons in the 3d orbital. With 5 electrons, 3 can be unpaired while 2 are paired.</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Total spin <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">S is <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">3/2=1.5.</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Multiplicity = <span style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-kerning: auto; font-optical-sizing: auto; font-feature-settings: normal; font-variation-settings: normal; font-variant-position: normal; font-stretch: normal; font-size: 1.21em; line-height: 1.2; font-family: KaTeX_Main, "Times New Roman", serif; text-rendering: auto;">2S+1=2×1.5+1=4.</li><li style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 0px; padding-left: 0.375em; display: block; min-height: 28px;">Therefore, the multiplicity for Fe³⁺ is 4.</li></ul></li></ol>Thanks a lot. Best regards, Kejiang<div class="gmail_quote"><div dir="auto" class="gmail_attr">On Wednesday, November 22, 2023 at 8:58:45 AM UTC+8 Kejiang Li wrote: </div><blockquote class="gmail_quote" style="margin: 0 0 0 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Dear Matthias, Thanks a lot for providing the information. Could you please provide your input file for CP2K for reference? Maybe I made a mistake somewhere. Best regards, Kejiang <div class="gmail_quote"><div dir="auto" class="gmail_attr">On Tuesday, November 21, 2023 at 11:29:14 PM UTC+8 Krack Matthias wrote: </div><blockquote class="gmail_quote" style="margin:0 0 0 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> <div lang="en-CH" link="blue" vlink="purple" style="word-wrap:break-word"> <div> Hi The EOS curve for FeO (2x2x2) looks fine for me (see attached plot) using PBE and the <a href="https://pubs.acs.org/doi/10.1021/acs.est.7b01670" rel="nofollow" target="_blank" data-saferedirecturl="https://www.google.com/url?hl=en&q=https://pubs.acs.org/doi/10.1021/acs.est.7b01670&source=gmail&ust=1700711703400000&usg=AOvVaw1OhvGHLj4XzaGoAoxFiSnm">suggested Hubbard U(eff) value of 1.9 eV for iron</a> with CP2K. Best Matthias <img border="0" width="800" height="600" style="width:8.3333in;min-height:6.25in" src="https://groups.google.com/group/cp2k/attach/a252141c4ca/image001.png?part=0.1&view=1" alt="A graph of a function Description automatically generated"> <div> <div></div></div></div></div><div lang="en-CH" link="blue" vlink="purple" style="word-wrap:break-word"><div><div><div> <div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm"> From: <a rel="nofollow">cp...@googlegroups.com</a> <<a rel="nofollow">cp...@googlegroups.com</a>> on behalf of Jürg Hutter <<a rel="nofollow">hut...@chem.uzh.ch</a>> Date: Tuesday, 21 November 2023 at 09:46 To: <a rel="nofollow">cp...@googlegroups.com</a> <<a rel="nofollow">cp...@googlegroups.com</a>> Subject: Re: [CP2K:19537] Re: Significant discontinuity in EOS curver for FeO </div> </div></div></div></div><div lang="en-CH" link="blue" vlink="purple" style="word-wrap:break-word"><div><div><div><div>Hi what is the setup for the QE calculation (cell, k-points, magnetization)? regards JH ________________________________________ From: <a rel="nofollow">cp...@googlegroups.com</a> <<a rel="nofollow">cp...@googlegroups.com</a>> on behalf of Kejiang Li <<a rel="nofollow">lyam_...@126.com</a>> Sent: Monday, November 20, 2023 2:26 AM To: cp2k Subject: [CP2K:19531] Re: Significant discontinuity in EOS curver for FeO Dear all, To add one more point. As it was said, using a reference cell might solve this problem (<a href="https://groups.google.com/g/cp2k/c/N52jLt2yAIQ/m/JAlV3KTVUtIJ" rel="nofollow" target="_blank" data-saferedirecturl="https://www.google.com/url?hl=en&q=https://groups.google.com/g/cp2k/c/N52jLt2yAIQ/m/JAlV3KTVUtIJ&source=gmail&ust=1700711703401000&usg=AOvVaw2DG0AUJxRWvG_ntxrFt3Xm">https://groups.google.com/g/cp2k/c/N52jLt2yAIQ/m/JAlV3KTVUtIJ</a>). You will notice that I used &CELL_REF in my input script, which did not solve my problem. Thanks. Kejiang On Monday, November 20, 2023 at 9:00:11 AM UTC+8 Kejiang Li wrote: Dear CP2K community, I am calculating the EOS for FeO with a 2*2*2 supercell. But there is always a significant discontinuity (sharp decrease) in the range of 4.3-4.4 angstrom lattice constant in the EOS curves, as shown in the figures below. I have done the following tests: - the convergence of the energy with different cutoffs; - using different functionals, including PBE, HSE, and SCAN; -including HSE with different HF fractions; -using different magnetization and +U settings. However, all the tests produce similar results with an apparent discontinuity (4.3-4.3 A) . This discontinuity is not observed in the Quantum Espresso results conducted by myself and in the results of literature that generally used VASP. I believe that the CP2K program might cause this problem. Can you give me more suggestions on how to do further tests? Here, I also attached one sample code I used during my tests. Thanks a lot. Best regards, Kejiang The University of Science and Technology Beijing [cp2k_functionals.jpg] [cp2k_mag_u.jpg][cp2k_mag_u2.jpg] -- You received this message because you are subscribed to the Google Groups "cp2k" group. 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