We have performed folded-diagram G-matrix calculations of the particle
-hole effective interaction for the hypernucleus O-16(Lambda), using b
oth the Nijmegen soft-core and the Julich-B hyperon-nucleon potentials
. Significant differences between the energy spectra given by these tw
o potentials are noticed. The effects of the folded diagrams and the e
ffective three-body force induced by Lambda-Sigma coupling are found i
o be important.