Symmetric Triple Well with Non-Equivalent Vacua: Instantonic Approach
  We show that for the triple well potential with non-equivalent vacua, instantons generate for the low lying energy states a singlet and a doublet of states rather than a triplet of equal energy spacing. Our energy splitting formulae are also confirmed numerically. This splitting property is due to the presence of non-equivalent vacua. A comment on its generality to multi-well is presented. 
H. A. Alhendi and E. I. Lashin