  We define 2-crossed module bundle 2-gerbes related to general Lie 2-crossed
modules and discuss their properties. A 2-crossed module bundle 2-gerbe over a
manifold is defined in terms of a so called 2-crossed module bundle gerbe,
which is a crossed module bundle gerbe equipped with an extra sructure. It is
shown that string structures can be described and classified using 2-crossed
module bundle 2-gerbes.

Differential Geometry;Algebraic Topology