being smaller in size than Nd(III) prefers smaller CN compared to Nd(III). In the case of three PF6 - complex has the highest 𝐵𝐵𝐵𝐵 𝑃𝑃𝑃𝑃 6 - among all structures, and the Yb 58CN complex is identified as the second most stable with only 0.9 kcal/mol lower 𝐵𝐵𝐵𝐵 𝑃𝑃𝑃𝑃 6 - .