Probing the multiple (δ- and π-) aromaticity of [Hf3F3]− anion, [Hf3F3X2]+ (X = Li, Na, and K), and [Hf3F3Y]+ (Y = Be and Mg) clusters

The top-five valence MOs responsible for the planar triangular Hf3 framework in the [Hf3F3]− (D3h, 1A1′).