  A first-principle multiscale modeling approach is presented, which is derived
from the solution of the Ornstein-Zernike equation for the coarse-grained
representation of polymer liquids. The approach is analytical, and for this
reason is transferable. It is here applied to determine the structure of
several polymeric systems, which have different parameter values, such as
molecular length, monomeric structure, local flexibility, and thermodynamic
conditions. When the pair distribution function obtained from this procedure is
compared with the results from a full atomistic simulation, it shows
quantitative agreement. Moreover, the multiscale procedure accurately captures
both large and local scale properties while remaining computationally
advantageous.
