  We investigate the ground state of the Kondo necklace model on
geometrically-frustrated lattices by the variational Monte Carlo simulation. To
explore the possibility of a partially-ordered phase, we employ an extension of
the Yosida-type wave function as a variational state, which can describe a
coexistence of spin-singlet formation due to the Kondo coupling and magnetic
ordering by the Ruderman-Kittel-Kasuya-Yosida interaction. We show the
benchmark of the numerical simulation to demonstrate the high precision brought
by the optimization of a large number of variational parameters. We discuss the
ground-state phase diagram for the model on the kagome lattice in comparison
with that for the triangular-lattice case.
