Dear all, Recently, we encountered a problem (probably caused by memory) when performing a non self-consistent calculation of a big system (more than 3,500 atoms). CP2K printed out the overlap matrix (AO*Log file, 67 GB) smoothly but always aborted when printing the MO eigenvectors & eigenvalues (MO*Log files). By increasing the amount of memory per process up to 24 GB per process, a smaller system (2000atoms) worked out, but the 3500 atoms still fails even with up to 256 GB memory/process. Since we have performed the geometry optimization for this big system with quite some efforts, the more important thing for us is to calculate some physical property based MO eigenvalues. So I wonder if any of you have met this kind of problem or do you have any suggestion about it. Any help will be highly appreciated! Thanks a lot in advance! PS: I have tried it with both an old stable version and the most recent one from the trunck. Best Wishes Wei