Fluctuation/Correlation Effects on Block Copolymer Self-Assembly 

We perform both polymer self-consistent field (SCF) calculations and Langevin dynamics (LD) simulations using the same dissipative particle dynamics chain (DPDC) model—comprising discrete Gaussian chains with DPD nonbonded pair potentials—for linear diblock copolymers (A-B) and miktoarm triblock terpolymers (ABC stars). This allows us to quantitatively assess the effects of system fluctuations and correlations that are inherently neglected in SCF theory. SCF calculations are carried out using PSCF+ (https://github.com/qwcsu/PSCFplus), while LD simulations are performed with HOOMD via an automated Excel-integrated workflow. We find that SCF theory consistently overestimates the bulk period of self-assembled structures by approximately 5~15%, regardless of morphology—lamellae, cylinders (including various tiling patterns formed by ABC stars), or spheres. A detailed comparison of structural and thermodynamic properties from SCF calculations and LD simulations highlights the limitations of the mean-field approximation used in SCF theory for quantitatively describing the ordered morphologies of block copolymer self-assembly.