Figure 1.

The two-dimensional triplet He${}_2$H${}^{+}$ PES in eV for the motion of the hydrogen atom (gray square) around the fixed positions of the helium atoms (purple circles) in the ${}^2{\mathsf{\Sigma }}_u$ He${}_2$${}^{+}$ molecule with one shown on the x-axis. The minimum corresponds to the geometry of the ${}^3{B}_1$ state, 10.90 eV above the minimum of the ground ${}^1{\mathsf{\Sigma }}_g^{+}$ state.