Figure shows that FDA embedding with the +2 charge of Mg 2+ in MgG 4 leads to mixing of the three pairs of site states with respect to the FDA embedding in G 4 . In particular, 3 ππ * 1 and 3 ππ * 2 mix to produce 3 ππ * 3 and 3 ππ * 4 (see Table for the expansions of the site states). The same happens with the corresponding singlet states ( 1 ππ * 1 and 1 ππ * 2 mix to form 1 ππ * 3 and 1 ππ * 4 ). The third pair of mixing site states are 1 nπ * 1 and 1 nπ * 2 , producing 1 nπ * 3 and 1 nπ * 4 . It is also interesting to note that embedding with only the +2 charge of magnesium stabilized the 1 πRy 6 state, which now corresponds to the S 2 state. This is due to the fact that the Rydberg density in front of the NH 2 group is sufficiently close to the Mg cation to induce a stabilization effect via their attractive interaction.