Generalized random phase approximation method for phase separation of polymer melt

We develope a dynamical TDGL simulation method using the RPA approximation. This method is based on linear operations and the expression of the free energy of the system is more accurate and simple than the recently proposed generalized Ohta-Kawasaki theory. Melts of any blends of polymers with arbitrary architectures can be simulated using this theory. As the numerical simulations using this method is faster than the standard SCF simulations, our method can be used to produce an initial guess of the phase separated structures for the SCF simulation. A 3D hexiagonally packed cylinder structure is successfully reproduced using this method.