<div dir="ltr">Dear CP2K community, I have been trying for a few days to set up calculations of graphite as an exercise for a student but I am getting the weirdest results. I am sure in the it will end up being a silly mistake in the input, but I can't get to see it so perhaps someone can help. Despite using a fairly large FD smearing, the SCF cycle has a hard time converging, and when the maximum number of steps is reached 50 Broy./Diag. 0.50E+00 1.2 0.00014351 -819.2909959720 -2.28E-09 *** SCF run NOT converged *** and the calculation carries on with what it has got, diagnostics are really strange. For a start, eigenvalues show two weird very low-energy states MO EIGENVALUES AND MO OCCUPATION NUMBERS # MO index MO eigenvalue [a.u.] MO occupation 1 -21.523076 2.000000 2 -21.517160 2.000000 3 -1.383548 2.000000 4 -0.510418 2.000000 forces on the atoms are insane ATOMIC FORCES in [a.u.] # Atom Kind Element X Y Z 1 1 C 4.68736611 4.63921800 -222.86999309 2 1 C -1.57720920 -4.48651652 124.33822840 3 1 C -5.01734639 3.10518104 176.16292919 and so is the stress tensor STRESS TENSOR [GPa] X Y Z X -8233.84728056 8.05482610 0.90481573 Y 8.05482610 -9552.76932222 -0.49445437 Z 0.90481573 -0.49445437 -2526.59040628 I was thinking of an error in the structure or the cell parameters, but I checked it many times and everything seems in order. The same structure, with same functional and similar parameters in SIESTA converges like a stone, and gives no problem whatsoever. Can you spot something obvious that I am missing? I'd really like to use CP2K for this exercise, but I can't seem to figure out what is going wrong. Many thanks, Michele </div>