Comparing the NPA charges between Nd-complexes and Yb-complexes, it can be seen that the decrease of NPA charge on the Yb-center after binding with PF6 -anions is more compared to Nd-complexes. This implies a greater amount of charge transfer from PF6 -anions to the Yb-center than the Nd-center, justifying the stronger bonding for Yb-center and hence greater 𝐵𝐵𝐵𝐵 𝑃𝑃𝑃𝑃 6 - values for Yb-complexes.