(color online) Maps of the electron localization function (ELF) for uniaxial compression along the a axis at different strain levels in the plane containing the atoms in the chain (B and C and boron polar (B and equatorial (B atoms of icosahedra. (a) corresponds to the initial stage, (b) , (c) where the abrupt chain bending occurs but no extra bond is formed, (d) , (e) , (f) where the B₁₁C icosahedra are highly distorted but still not broken, (g) where the icosahedra are broken, leading to the formation of some extra new bonds, and (h) corresponds to an unrecoverable deformation.