Unveiling the electronic and structural consequences of removing two electrons from B 12 H 12 2 .

The notion that a regular icosahedron is unattainable in neutral B 12 H 12 has persisted for nearly 70 years. This is because 24 valence electrons are used for B-H bonds, while another 24 electrons are necessary to maintain the deltahedron, unlike the 26 used in the dianion. According to Wade-Mingos rules, the neutral system should be a deltahedron with a capped face. Nevertheless, our exploration of the potential energy surface of B 12 H 12 reveals that the global minimum is a closed-shell form with an H 2 unit attached to a boron vertex of B 12 H 10 , preserving the deltahedral boron skeleton.