  We consider the localized modes (bright solitons) described by
one-dimensional quintic nonlinear Schrodinger equation with a periodic
potential. In the case of attractive nonlinearity we deduce sufficient
conditions for collapse. We show that there exist spatially localized modes
with arbitrarily large number of particles. We study such solutions in the
semi-infinite gap (attractive case) and in the first gap (attractive and
repulsive cases), and show that a nonzero minimum value of the number of
particles is necessary for a localized mode to be created. In the limit of
large negative frequencies (attractive case) we observe "quantization" of the
number of particles of the stationary modes. Such solutions can be interpreted
as coupled "Townes" solitons and appear to be stable. The modes in the first
gap have numbers of particles infinitely growing with frequencies approaching
one of the gap edges, which is explained by the power decay of the modes.
Stability of the localized modes is discussed.
