[warwick]

it is known that H₂ exists since the two electrons fill the sigma orbital, and leave the sigma* orbital alone, which has a lower energy state than the 1s orbitals of the individual atoms. 

it is often shown that He₂ does not exist since both sigma and sigma* are filled and the energy levels are no better than the fully-filled He 1s orbitals. 

however,  we often talk about atoms and molecules that are not electronically neutral  H⁺ for example.    One could imagine a case where He₂²⁺  would be stable since the sigma* anti orbital is now unfilled.   

so what gives?  with this concept,  all atoms can form molecules assuming that they have gained/lost charge,  but I have not found any discussion of how the molecules stability is effected by not being in the neutral state. 

an answer, or a good online reference would be much appreciated

[warwick]

*Ignore me, I am impatient*