Dear Developers,I am seeking advice regarding AIMD simulation of organic electrolyte (LIFSI and DME) in the bulk phase. The experimental density is 1.04 g/cm³. Below are the steps I have taken:<ol><li>Built the solution box (18.5 Å) using Material Studio.</li><li>Pre-equilibrated the system using classical MD with the COMPASS III force field in the NPT ensemble for 30 ns. The density is well equilibrated .Exported the last frame of the MD trajectory (closest to the target density of 1.04 g/cm³) to a CIF file, </li><li>ran AIMD simulations in CP2K (input file attached in the email).</li></ol> After 1 ps of aimd simulation, I found that the calculated density deviates significantly from the equilibrated value( (18.5 Å, ~1.04 g/cm³) ). Given the high computational cost of AIMD, I paused the simulation to seek advice before proceeding further, as I am concerned that the input file or simulation steps might be incorrect, leading to incorrect trajectories even with extended simulation time.<img alt="图片1.png" width="400px" height="247px" src="cid:e9c7e3d7-fcd4-4f0c-acf2-fdd02e6aec73" /><ol><li>In the output file, the pressure control seems poor. The average pressure over 1 ps is ~400 bar (set at 1 bar). How can I adjust the barostat parameters to improve this? Currently, the time constant is set to 100 fs.</li><li> For bulk electrolyte AIMD tasks, is it appropriate to use the DZVP-MOLOPT-SR-GTH basis set? Would this significantly impact the coordination structure of lithium ions?</li><li>What ensemble is more appropriate for AIMD simulations? I have heard that due to the small number of atoms in AIMD simulations, it is reasonable to run both pre-equilibration MD and AIMD in the NVT ensemble since the density cannot match experimental values. Is this correct?</li></ol>I would greatly appreciate any guidance on these points. -- 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/e1ff1329-8265-4045-842b-6d7989acbaban%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/e1ff1329-8265-4045-842b-6d7989acbaban%40googlegroups.com</a>.