<div dir="ltr">Dear Hamid, I'm not an expert in CP2K, but based on the XYZ file, it looks like the C60 molecule has been adsorbed in a distorted configuration. I'm not sure if you relaxed the slab before performing the adsorption, but if not, I recommend doing so. Alternatively, you could try fixing all the slab layers initially and allowing only the molecule to relax. Once the system converges, you can gradually release the top few layers of the slab (e.g., the top four layers) from the constraints. This approach may help you avoid the unexpected behavior you're observing. This is just a simple suggestion based on my understanding—please take it as friendly advice.</div> <div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Wed, Jul 9, 2025 at 5:47 AM hamid zabihi <<a href="mailto:hamidzabihiheshajin2023@gmail.com">hamidzabihiheshajin2023@gmail.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> Dear CP2K community, I am performing a geometry optimization of a C₆₀ molecule adsorbed on an Au(111) slab, using PBE+D3 and DZVP-MOLOPT-SR-GTH basis sets. The initial configuration had C₆₀ placed ~3 Å above the gold surface. However, after optimization, I noticed that several top-layer Au atoms were pulled significantly upward—toward the C₆₀. This distortion seems nonphysical and may indicate issues with my setup or parameters. I would be grateful for any advice on: <ul><li> Best practices for modeling molecule-surface interactions in CP2K </li><li> Ensuring slab stability and correct adsorption behavior </li><li> Whether this is a known issue with this CP2K version or functional </li></ul> System details: <ul><li> CP2K version: 8.0 (development) </li><li> Functional: PBE with D3 dispersion correction </li><li> Basis sets: DZVP-MOLOPT-SR-GTH </li><li> Slab: 4-layer Au(111), ~15 Å vacuum in y-direction, bottom layers unconstrained </li></ul> I’ve attached the following files: <ul><li> cp2k_c60_au_geoopt.inp: Input file </li><li> out-C60_Au_GEO_OPT.log: Optimization output </li><li> C60_Au_opt-trajectory.xyz-pos-1: Final trajectory </li></ul> Thank you in advance for your help! Best regards, Hamid Zabihi -- 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+unsubscribe@googlegroups.com" target="_blank">cp2k+unsubscribe@googlegroups.com</a>. To view this discussion visit <a href="https://groups.google.com/d/msgid/cp2k/87a552d7-53be-4277-90fe-76731650704dn%40googlegroups.com?utm_medium=email&utm_source=footer" target="_blank">https://groups.google.com/d/msgid/cp2k/87a552d7-53be-4277-90fe-76731650704dn%40googlegroups.com</a>. </blockquote></div> -- 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+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>. To view this discussion visit <a href="https://groups.google.com/d/msgid/cp2k/CAPzb9V8kiRKA6ZdDLAYSvBJpQYhWSh%2B0Pog3b0ZtC1ry4bnq1Q%40mail.gmail.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/CAPzb9V8kiRKA6ZdDLAYSvBJpQYhWSh%2B0Pog3b0ZtC1ry4bnq1Q%40mail.gmail.com</a>.