Comment on the free energy functional of block copolymer melts in the strong segregation limit

An elastic theory was previously developed for gently deformed periodic structures. However the elastic constants obtained are not consistent with those of Wang and Safran calculated recently by a different method. The main difference is the block ratio dependence of the equilibrium period D. Our result show a rather strong dependence of the block ratio f while Wang and Safran have derived D independent of f. The origin of the above discrepancy is explored