Microphase Separation Morphology in Multiblock Copolymer Melts Obtained from Monte Carlo Simulations A lattice polymer simulation method called diagonal bond method is discussed: Why does the method enable us to simulate complex morphologies? We demonstrate cell crystalline structures for ABCD star block copolymers, and cylindrical structures for asymmetric ABC star block copolymers. A common geometric constraint for these starblock copolymers is explicitly given. For ABC triblock copolymers, we have obtained four structures: gyroid, doublediamond, lamellar, and cylindrical structures. For all structures in this paper pictorial presentation is given. 
