  Complex behavior in glassforming liquids is associated with formation of a
mosaic of different structures. Using bond order parameters together with
topological characteristics of the bond network, we show that in the mosaic of
crystalline and amorphous clusters found in a 2D liquid the difference between
structural sub- components translates into a difference between two coexisting
phases. We suggest that the observed microphase separated mosaic is a 2D
realization of what is usually invoked to explain special features found in 3D
complex liquids. Conditions favoring mosaic stability are discussed; these
conditions include a new type of critical behavior and long-range correlations
between sub-component clusters.
