<div dir="ltr">Dear all I am trying to understand the meaning of global and subsystem configuration in a bsse calculation. I guess the sybsystem is simply the different parts of the system I would like to study, for instance AB I will define 2 fragment and then I will have subsystem 1 0 and 0 1. On the other hand I am lost in the possible meaning of global configuration, the only information I could find here on the group was an topic from which I've seen it is defined several time so I wonder if the input I found is correct and the meaning of it. &BSSE &FRAGMENT LIST ... &END FRAGMENT &FRAGMENT LIST .... &END FRAGMENT &CONFIGURATION GLB_CONF 1 1 SUB_CONF 1 1 &END &CONFIGURATION GLB_CONF 1 0 SUB_CONF 1 0 &END &CONFIGURATION GLB_CONF 0 1 SUB_CONF 0 1 &END &CONFIGURATION GLB_CONF 1 1 SUB_CONF 1 0 &END &CONFIGURATION GLB_CONF 1 1 SUB_CONF 0 1 &END &END BSSE what I would have done is GLB_CONF 1 1 SUB_CONF 1 1 GLB_CONF 1 1 SUB_COND 1 0 GLB_CONF 1 1 SUB_CONF 0 1 Nevertheless also in this case it seems strange to me have to define the global configuration so that I imagine I'm missing something. Any comment, advice or even link to examples which I could not find are more than welcome Cheers Davide </div>