Hello, I want to run a BSSE calculation for two charged fragments: fragment 1: a MOF with a net charge of -8 (multiplicity 1) fragment 2: an ion with a charge of +1 (multiplicity 1)<div>If my understanding is correct, ghost atoms have zero nuclear charge and only support a basis set. So I defined the following configurations - fragment 1 real: charge -8 - fragment 2 real: charge +1 - fragment 1 real, fragment 2 ghost: charge -8 - fragment 1 ghost, fragment 2 real: charge +1 - fragment 1 real, fragment 2 real: charge -7 Which gives me the following error: 'Use the LSD option for an odd number of electrons' Can someone tell me what the problem is? Running a geometry optimisation for this complex with a net charge of -7 and a multiplicity of 1 worked fine. I also attach the code snippet for the BSSE section. Thank you in advance </div><div> &BSSE &CONFIGURATION CHARGE -8 GLB_CONF 1 0 MULTIPLICITY 1 SUB_CONF 1 0 &END CONFIGURATION &CONFIGURATION CHARGE 1 GLB_CONF 0 1 MULTIPLICITY 1 SUB_CONF 0 1 &END CONFIGURATION &CONFIGURATION CHARGE -8 GLB_CONF 1 1 MULTIPLICITY 1 SUB_CONF 1 0 &END CONFIGURATION &CONFIGURATION CHARGE 1 GLB_CONF 1 1 MULTIPLICITY 1 SUB_CONF 0 1 &END CONFIGURATION &CONFIGURATION CHARGE -7 GLB_CONF 1 1 MULTIPLICITY 1 SUB_CONF 1 1 &END CONFIGURATION &FRAGMENT LIST 1..844 &END FRAGMENT &FRAGMENT LIST 845..855 &END FRAGMENT &END BSSE</div> -- 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/d186828d-a497-424b-95a4-56172f9e14f1n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/d186828d-a497-424b-95a4-56172f9e14f1n%40googlegroups.com</a>.