Stress in Self-Consistent-Field Theory

A perturbation theory was developed to determine the state of mechanical stress in a nonequilibrium unit cell. The theory was used to calculate derivatives of the free energy in self-consistent-field theory (SCFT) of block copolymer crystals with respect to the changes in the parameters of the unit cell. It was found that the calculated stress vanished which helped in finding the unit cell that minimized the free energy in a time comparable to that required to solve the SCFT equations for a fixed unit cell.