Ab initio calculations were performed for several suggested mechanisms of energy transfer between
helium metastable particles and neon. Optimized geometries and excited-state energies were calculated
for neon excited-state complexes and the convergence properties of the non-additive contributions to
the interaction energies were examined. The most probable excitation-transfer mechanism was found to be
Hem2
(a3Σ+
u )+Ne → (He2Ne)
∗
r
→ Ne(2p53s)+2He based on an energy difference of 0.0674 eV between the
triplet excited state of Hem2
and the singlet excited state of (HeNeHe)
∗
r. No theoretical evidence was found
for the production of neon singlet excited-state complexes other than 20.0858 to 20.4875 eV by the considered
two-, three- and four-body models of energy transfer processes. The energy curves of the reactions
involving the excited-state complexes (HeNeHe)
∗
r and (HeNe)
∗
r are provided and compared with the previously
reported experimental results on the reaction Hem2
(a3Σ+
u )+Ne → (He2Ne)
∗
r
→ Ne(2p53s)+2He. The
relation between the probability of energy transfer and laser activity is discussed. The non-additive contribution
to the total interaction energy of the nominated (HeNeHe)
∗
r intermediate complex was found to be
negligible, pointing to the possibility of constructing model potentials and simulation of larger systems.