Dear Users, I am reaching out as I am uncertain about the correct assignment of NEL values in the BS routine. The system under investigation consists of a molecule with a central Cu2+ atom coordinating two ligands in a square planar geometry. In a standard spin density calculation (UPBE/DZVP-MOLOPT) with a multiplicity of two, the spin densities are well reproduced, with the unpaired electron localized precisely on the copper atom. The Hirshfeld output reports the following values: Element Kind Ref Charge Population Spin moment Net charge Cu 4 11.000 6.182 5.514 0.668 -0.695 My objective is to replicate this result using the BS approach. For a Cu2+ ion, I assume the configuration should be as follows: &KIND Cu &BS ON &ALPHA L = 0 2 N = 4 3 NEL = -2 ? &END &BETA L = 0 2 N = 4 3 NEL = -2 ? &END &END I have conducted several tests; however, I am unable to obtain the correct number of valence electrons and the expected multiplicity in the output. I have attached the input file for reference (opt.inp). I would be sincerely grateful for any suggestions regarding the appropriate assignment of the NEL values. Best regards, Lorenzo Briccolani -- 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 visit <a href="https://groups.google.com/d/msgid/cp2k/7b7ad053-f176-49f2-a9ea-0580b9d0d584n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/7b7ad053-f176-49f2-a9ea-0580b9d0d584n%40googlegroups.com</a>.