  We describe the application of the lattice covering problem to the placement
of templates in a search for continuous gravitational waves from the low-mass
X-Ray binary Scorpius X-1. Efficient placement of templates to cover the
parameter space at a given maximum mismatch is an application of the sphere
covering problem, for which an implementation is available in the LatticeTiling
software library. In the case of Sco X-1, potential correlations, in both the
prior uncertainty and the mismatch metric, between the orbital period and
orbital phase, lead to complications in the efficient construction of the
lattice. We define a shearing coordinate transformation which simultaneously
minimizes both of these sources of correlation, and allows us to take advantage
of the small prior orbital period uncertainty. The resulting lattices have a
factor of about 3 fewer templates than the corresponding parameter space grids
constructed by the prior straightforward method, allowing a more sensitive
search at the same computing cost and maximum mismatch.
