Intra-chain pair density function

Fig. 9a, b. Intra-chain pair density function radial distance a dotted curve result of bulk NPT Monte Carlo simulation of a 32-chain 24-mer (n-tetracosane) system at 450 K and 0.1 MPa dashed curve result from fast sampling of continuous unperturbed chains curves are neatly identical b dotted curve result from bulk NPT Monte Carlo simulation of a 10-chain 78-mer ( polyethylene ) system at 450 K and 0.1 MPa dashed curve result from fast sampling of continuous unperturbed chains... 

Figures 9b and 11b show tte intra-chain pair density function and the interchain pair distribution function, respectively, for a system of 10 chains of 78 units each ( polyethylene ) at 450 K and 0.1 MPa. We see in Fig. 9b the increase in the size and density of the segment doud with increase in chain length relative to the n-tetracosane system. Fig. 9a. In Fig. 11b the correlation hole now appears much stronger than for the n-tetracosane system.

The intra-chain pair density functions obtained from both the bulk simulation and the continuous unperturbed chains were used as input to the polymer-RISM integral equation for estimating the intermolecular pair distribution function g(r) (using a soft-Percus Yevick closure). We found that PRISM underpredicts the first peak in g(r), while also overpredicting the steefmess of the rise to the first peak. 

By combining the intra-chain pair density and the inter-chain pair distribution functions we can form the total pair distribution function g (r) ... 

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