Let's say I have a system of N atoms with M of them not constrained. I want to calculate the energy and forces of the system only considering the interactions between M and the N atoms, not between N atoms. Basically, can I exclude the interactions amongst N-M atoms? Sure this would not give you the correct total energy, but is this directly available in CP2K, to do something like this? For a purpose I want to use this for, it would significantly cut down on the calculation time and limit memory usage. -- 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/7fb3273d-3d14-4946-8ef0-22c3f1ba0812n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/7fb3273d-3d14-4946-8ef0-22c3f1ba0812n%40googlegroups.com</a>.