  We present a complete analysis of the laser control of a model molecular
system using both optimal control theory and adiabatic techniques. This
molecule has a particular potential energy surface with a bifurcating region
connecting three potential wells which allows a variety of processes such as
isomerization, tunnelling or implementation of quantum gates on one or two
qubits. The parameters of the model have been chosen so as to reproduce the
main features of H3CO which is a molecule-benchmark for such dynamics. We show
the feasibility of different processes and we investigate their robustness
against variations of laser field. We discuss the conditions under which each
method of control gives the best results. We also point out the relation
between optimal control theory and local control.
