As the distance between these negatively polarized sites is significantly shorter for F@Si6_2 (Figure ), a larger electrostatic repulsion arises. Finally, the low energy of the F@Si1_2 position is noteworthy. Here, one of the surrounding oxygen atoms acts as hydrogen bond acceptor for the These observations underline that it is challenging to discern the individual factors determining the energetically preferred fluoride location in a given system, as there are few generalizable rules.