Details about the only scientific study ever to have focussed on negative multiple charged onions. That particular focus came in the form of a typo:
“… the atomic stabilization of negative multiple charged onions in linearly polarized super-intense high-frequency laser field in 3-dimensional space using both frequency independent and dependent potentials.“
– recently published by doctorial candidate Qi Wei at the Department of Chemistry at Purdue University, US.
The thesis : Stability of atomic and molecular systems in strong external fields also evaluated the stability of gas phase atomic anions in a superintense laser field.