<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="DE-CH" link="blue" vlink="purple"> <div class="WordSection1"> <p class="MsoNormal"><span style="mso-fareast-language:EN-US">Dear Aniruddha<o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">UKS is certainly a good idea. There is also the possibility of an open shell singlet. I would check the literature concerning the choice of the functional.<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Best<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Matthias<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p> <p class="MsoNormal"><b><span lang="DE">Von:</span></b><span lang="DE"> cp...@googlegroups.com <...@googlegroups.com> <b>Im Auftrag von </b>Aniruddha Dive<br> <b>Gesendet:</b> Sonntag, 14. Oktober 2018 01:13<br> <b>An:</b> cp2k <...@googlegroups.com><br> <b>Betreff:</b> Re: [CP2K:10844] Bond Dissociation Energy Calculation<o:p></o:p></span></p> <p class="MsoNormal"><o:p> </o:p></p> <div> <div> <p class="MsoNormal">Thanks Matthais,<o:p></o:p></p> </div> <div> <p class="MsoNormal"><o:p> </o:p></p> </div> <div> <p class="MsoNormal">Does it mean that I need to use Unrestricted Kohn-Sham? Also currently I am doing a singlet calculations, should I do an triplet calculations for better results?<o:p></o:p></p> </div> <div> <p class="MsoNormal"><o:p> </o:p></p> </div> <div> <p class="MsoNormal">Is REVPBE okay or should I go ahead with B3LYP XC and BLYP pseudopotentials? <o:p></o:p></p> </div> <div> <p class="MsoNormal"><o:p> </o:p></p> </div> <div> <p class="MsoNormal">Regards,<o:p></o:p></p> </div> <div> <p class="MsoNormal">Aniruddha M Dive<o:p></o:p></p> </div> <p class="MsoNormal"><br> On Friday, October 12, 2018 at 12:49:40 PM UTC-7, Matthias Krack wrote:<o:p></o:p></p> <blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm"> <div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hi <span lang="EN-GB">Aniruddha</span><o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">It seems that you are using restricted Kohn-Sham (RKS) which constrains the state of the fragments. Consider the simple<span lang="EN-GB"> text</span>book case of H2. RKS allows only for the fragments H+ and H- if you pull the H atoms apart.<o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="FR-CH">HTH</span><o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="FR-CH"> </span><o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="FR-CH">Matthias</span><o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="FR-CH"> </span><o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span lang="DE">Von:</span></b><span lang="DE"> <a href="javascript:" target="_blank">cp...@googlegroups.com</a> <<a href="javascript:" target="_blank">cp...@googlegroups.com</a>> <b>Im Auftrag von </b>Aniruddha Dive<br> <b>Gesendet:</b> Freitag, 12. Oktober 2018 20:19<br> <b>An:</b> cp2k <<a href="javascript:" target="_blank">cp...@googlegroups.com</a>><br> <b>Betreff:</b> [CP2K:10842] Bond Dissociation Energy Calculation</span><o:p></o:p></p> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> <div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hi All,<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I am trying to calculate the bond dissociation energy of Si-S bond using CP2K. Please find attached my input file for the same. <o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I am initially performing a geometry optimization of a SiH3-SH molecule to calculate the equilibrium Si-S bond length. Once I have the equilibrium bond length, I am varying the Si-S distance from 1.5 A to 7.5 A. I rerun geometry optimization for these different structures keeping the Si and S atoms fixed while allowing the other H atoms to relax. <o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Kindly let me know if this input files and approach looks good. I am getting the bond dissociation energy to be 100 kcal/mol whereas the literature value is ~ 145 kcal/mol<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Regards,<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Aniruddha M Dive<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Phd Candidate<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Washington State University<o:p></o:p></p> </div> </div> <p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">-- <br> You received this message because you are subscribed to the Google Groups "cp2k" group.<br> To unsubscribe from this group and stop receiving emails from it, send an email to <a href="javascript:" target="_blank">cp2k+u...@googlegroups.com</a>.<br> To post to this group, send email to <a href="javascript:" target="_blank">cp...@googlegroups.com</a>.<br> Visit this group at <a href="https://groups.google.com/group/cp2k" target="_blank"> https://groups.google.com/group/cp2k</a>.<br> For more options, visit <a href="https://groups.google.com/d/optout" target="_blank"> https://groups.google.com/d/optout</a>.<o:p></o:p></p> </div> </div> </blockquote> </div> <p class="MsoNormal">-- <br> You received this message because you are subscribed to the Google Groups "cp2k" group.<br> To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsu...@googlegroups.com">cp2k+unsu...@googlegroups.com</a>.<br> To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>.<br> Visit this group at <a href="https://groups.google.com/group/cp2k">https://groups.google.com/group/cp2k</a>.<br> For more options, visit <a href="https://groups.google.com/d/optout">https://groups.google.com/d/optout</a>.<o:p></o:p></p> </div> </body> </html>