Correlation Effects in Various Polymer Density-Functional Theories

While the widely used polymer self-consistent field theory (SCFT) neglects the effects of system fluctuations and correlations, the latter can be captured by various polymer density-functional theories (PDFTs). Here we directly compare the results of various PDFTs, including those proposed by Yu and Wu (YW), by Chapman and co-workers (miSAFT), and by Donley et al. (CMS-RW), to the results of SCFT and Monte Carlo simulations for selected model systems. We put these PDFTs in a unified computational framework, the same as that of SCFT, and unambiguously quantify the correlation effects that they capture. Our work also reveals the relations among these theories and their computational complexity.