Hi everyone, I'm working on simulating the NPT ensemble dynamics of crystal materials aiming for a target temperature of 300K with CP2K version 2023.1. Initially, I planned to run the simulation for 1000 steps over 500fs. However, I encountered an issue at step 802. Fortunately, I haven't lost any data from those first 802 steps. Here are the details on the temperature changes and the changes in the supercell volume: I've also included the input file (with coordinates removed) and the output file (I've omitted repetitive information at the midway point). Here are my questions: 1) There were no error messages in the output file. Could someone help me figure out what went wrong? 2) The temperature seems to plateau at 232.6K, despite my setting it to 300K. I understand that I might not have completed enough steps (missing nearly 200 steps), and the heating time constant might be set too high (300 fs, with 400 fs already completed). However, shouldn't the temperature still continue to rise? 3) Why does the volume keep increasing even when the temperature stops rising? What could be causing the volume to continuously expand? Additional Insights: 1) I've conducted simulations on several structures with identical parameters, encountering similar issues across the board. This suggests the problem isn't just a random occurrence. Some simulations completed, while others, like the one in question, nearly didn't. Notably, simulations that didn't complete showed no error messages. However, completed or not, none of the simulations achieved the target temperature, and all experienced a continuous increase in volume. 2)The simulations are based on experimental crystal structures and were directly subjected to dynamic simulations without prior optimization. Although there was no disintegration of the structure, there was a noticeable, consistent increase in the distance between molecules, suggesting expansion. Thanks for any insights you can provide. -- 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 on the web visit <a href="https://groups.google.com/d/msgid/cp2k/f194924c-6ed0-4440-81f9-61a9d1624c0en%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/f194924c-6ed0-4440-81f9-61a9d1624c0en%40googlegroups.com</a>.