The Coulombic systems ( \alpha pe ) and ( \alpha \alpha e ) , ( \alpha ppe ) , ( \alpha \alpha pe ) and ( Li ^ { 3 + } Li ^ { 3 + } e ) placed in a magnetic field B \gtrsim 10 ^ { 11 } \mbox { G } are studied .
It is demonstrated a theoretical existence of the exotic ion ( HeH ) ^ { 2 + } for B \gtrsim 5 \times 10 ^ { 12 } \mbox { G } in parallel configuration ( the magnetic field is directed along internuclear axis ) as optimal as well as its excited states 1 \pi, 1 \delta .
As for the exotic ion { He } _ { 2 } ^ { 3 + } it is shown that in spite of strong electrostatic repulsion of \alpha - particles this ion can also exist for B \gtrsim 100 \mbox { a . u . } ( = 2.35 \times 10 ^ { 11 } \mbox { G } ) in parallel configuration as optimal in the states 1 \sigma _ { g } ( ground state ) , 1 \pi _ { u } , 1 \delta _ { g } .
Upon appearance both ions are unstable towards dissociation with He ^ { + } in the final state but with very large lifetime .
However , at B \gtrsim 10000 a.u .
the ion ( HeH ) ^ { 2 + } becomes stable , while at B \gtrsim 1000 a.u .
the ion { He } _ { 2 } ^ { 3 + } becomes stable .
With a magnetic field growth , both exotic ions become more and more tightly bound and compact , their lowest rotational and vibrational energies grow .
At the edge of applicability of non-relativistic approximation , B \sim 4.414 \times 10 ^ { 13 } G , there are indications that three more exotic linear ions ( H - He - H ) ^ { 3 + } , ( He - H - He ) ^ { 4 + } and even Li _ { 2 } ^ { 5 + } in parallel configuration may also occur .