According to MP2, CCD, and CCSD(T) calculations, H 3 BOBeHe ( 1 A 1 ) is a helium compound potentially observable as a metastable species. In fact, it is stable with respect to He and BH 3 detachment, and is separated by a barrier of ca. 3kcalmol −1 from the more stable H 2 B–O–BeH and He. In addition, its He detachment energy of nearly 5–6kcalmol −1 is almost twice that of OBeHe. This suggests that, using suited neutral Lewis acids, an otherwise poor helium acceptor could be activated so to fix the lightest noble gas. Confirming this prediction is a challenge for future ‘computational experiments’.