  We investigate by Molecular Dynamics simulation a system of $N$ particles
moving on the surface of a two-dimensional sphere and interacting by a
Lennard-Jones potential. We detail the way to account for the changes brought
by a nonzero curvature, both at a methodological and at a physical level. When
compared to a two-dimensional Lennard-Jones liquid on the Euclidean plane,
where a phase transition to an ordered hexagonal phase takes place, we find
that the presence of excess defects imposed by the topology of the sphere
frustrates the hexagonal order. We observe at high density a rapid increase of
the relaxation time when the temperature is decreased, whereas in the same
range of temperature the pair correlation function of the system evolves only
moderately.
