Dear users and developers of CP2K, I am a new user of CP2K. I want to use CP2K to simulate the DFT of a polymer crystal, which contains ~2500 atoms (C, N, O, H). This initial crystal conformation was suggested by the experimenters, and I need to optimize this structure to find the minimal energy state. I'm considering using CP2K due to its ability to do periodic DFT calculations. My question is related to what DFT functional and basis sets can be used to optimize a periodic crystal structure if such a massive system is considered? Maybe some there exists some examples of an input file for the problem of optimizing crystal systems using periodic boundary conditions? For these calculations, I have a workstation with an AMD Ryzen 5950x and 64 GB of memory. Also, is it possible to speed up the calculation with the GPU? Best wishes, Victor -- 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/a3774816-3e1c-4b29-9fe3-4aa1573281ecn%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/a3774816-3e1c-4b29-9fe3-4aa1573281ecn%40googlegroups.com</a>.