Dear CP2K Developers and Users, I am writing to ask two questions related to CP2K simulations: <ol> <li> 2D Slab Without Vacuum I am interested in modeling a 2D slab of liquid without introducing vacuum along the non-periodic direction (e.g., the z-axis). I have already set the Poisson solver to PERIODIC XY and changed the cell periodicity from XYZ to XY. My question is: Are these two settings indeed sufficient to correctly model a 2D slab without any vacuum in the non-periodic direction, or is additional setup required? </li> <li> Region-Based QM/MM Partitioning Is it possible in CP2K to define the QM, QM/MM and MM regions based on spatial regions (e.g., z-axis areas) rather than using fixed atom indices? This would be especially helpful for systems like liquids, where atoms move across layers during simulation. </li> </ol> Thank you, Elham -- 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/d1993aa7-7044-4c1f-9e9d-26a814e1182an%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/d1993aa7-7044-4c1f-9e9d-26a814e1182an%40googlegroups.com</a>.