Chain center-of-mass correlations

[tgartner]

It would be interesting to build in functionality that would allow the calculation of chain center-of-mass correlation functions from a solved PRISM object. See the below two papers for the general idea:

1. V. Krakoviack, J. P. Hansen and A. A. Louis, Europhys. Lett., 58 (1), pp. 53–59 (2002). DOI: 10.1209/epl/i2002-00605-7
2. V. Krakoviack, B. Rotenberg, and J.-P. Hansen, J. Phys. Chem. B 2004, 108, 6697-6706. DOI: 10.1021/jp036800o

Equation 16 of ref 1 allows for the calculation of the total correlation function between chain centers of mass (h_cc), provided one knows the intramolecular correlation function between monomers (omega_mm), the intramolecular correlation function between monomers and the chain center of mass (omega_cm), and the total correlation function between monomers (h_mm).

The debyer module could be extended to calculate both omega_mm and omega_cc from a simulation trajectory, and then a calculate class could be added that performs the calculation in equation 16 of ref 1.