Polymer Reference Interaction Site Model (PRISM) theory describes the equilibrium spatial-correlations of liquid-like polymer systems including melts, blends, solutions, block copolymers, ionomers, liquid crystal forming polymers and nanocomposites. Using PRISM theory, one can calculate thermodynamic (e.g., second virial coefficients, Flory-Huggins interaction parameters, potentials of mean force) and structural (eg., pair correlation functions, structure factors) information for these macromolecular materials. pyPRISM is a Python-based, open-source framework for conducting PRISM theory calculations. This framework aims to simplify PRISM-based studies by providing a user-friendly scripting interface for setting up and numerically solving the PRISM equations. pyPRISM also provides data structures, functions, and classes that streamline PRISM calculations, allowing pyPRISM to be extended for use in other tasks such as the coarse-graining of atomistic simulation force-fields or the modeling of experimental scattering data. The goal of this framework is to reduce the barrier to correctly and appropriately using PRISM theory and to provide a platform for rapid calculations of the structure and thermodynamics of polymeric fluids and nanocomposites.
If you use pyPRISM in your work, we ask that you please cite both of the following articles
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Martin, T.B.; Gartner, T.E III; Jones, R.L.; Snyder, C.R.; Jayaraman, A.; pyPRISM: A Computational Tool for Liquid State Theory Calculations of Macromolecular Materials, Macromolecules, 2018, 51 (8), p2906-2922 link
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Schweizer, K.S.; Curro, J.G.; Integral Equation Theory of the Structure of Polymer Melts, Physical Review Letters, 1987, 58 (3) p246-249 link
Below is an example python script where we use pyPRISM to calculate the pair correlation functions for a nanocomposite (polymer + particle) system with attractive polymer-particle interactions. Below the script is a plot of the pair correlation functions from this calculation. See here for a more detailed discussion of this example.
import pyPRISM
sys = pyPRISM.System(['particle','polymer'],kT=1.0)
sys.domain = pyPRISM.Domain(dr=0.01,length=4096)
sys.density['polymer'] = 0.75
sys.density['particle'] = 6e-6
sys.diameter['polymer'] = 1.0
sys.diameter['particle'] = 5.0
sys.omega['polymer','polymer'] = pyPRISM.omega.FreelyJointedChain(length=100,l=4.0/3.0)
sys.omega['polymer','particle'] = pyPRISM.omega.InterMolecular()
sys.omega['particle','particle'] = pyPRISM.omega.SingleSite()
sys.potential['polymer','polymer'] = pyPRISM.potential.HardSphere()
sys.potential['polymer','particle'] = pyPRISM.potential.Exponential(alpha=0.5,epsilon=1.0)
sys.potential['particle','particle'] = pyPRISM.potential.HardSphere()
sys.closure['polymer','polymer'] = pyPRISM.closure.PercusYevick()
sys.closure['polymer','particle'] = pyPRISM.closure.PercusYevick()
sys.closure['particle','particle'] = pyPRISM.closure.HyperNettedChain()
PRISM = sys.solve()
pcf = pyPRISM.calculate.prism.pair_correlation(PRISM)
The commands below should install pyPRISM with all basic dependences via conda or pip. These commands should be platform agnostic and work for Linux, macOS, and Windows if you have Anaconda or pip installed. For full installation instructions please see the documentation.
$ conda install -c conda-forge pyPRISMor
$ pip install pyPRISMCode documentation is hosted on pyprism.readthedocs.io. The most up to date code documentation can always be found by compiling from source.
Please use the Issue tracker to submit questions or suggestions for the project. For other correspondence, please contact one of the team-members below.
- Dr. Tyler Martin, NIST, GitHub, Webpage, Scholar
- Dr. Thomas Gartner, Princeton University, GitHub, Scholar
- Dr. Ronald Jones, NIST, Webpage, Scholar
- Dr. Chad Snyder, NIST, Webpage, Scholar
- Prof. Arthi Jayaraman, University of Delaware, Webpage, Scholar
Any identification of commercial or open-source software in this document is done so purely in order to specify the methodology adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the softwares identified are necessarily the best available for the purpose.
This software was developed by employees of the National Institute of Standards and Technology (NIST), an agency of the Federal Government and is being made available as a public service. Pursuant to title 17 United States Code Section 105, works of NIST employees are not subject to copyright protection in the United States. This software may be subject to foreign copyright. Permission in the United States and in foreign countries, to the extent that NIST may hold copyright, to use, copy, modify, create derivative works, and distribute this software and its documentation without fee is hereby granted on a non-exclusive basis, provided that this notice and disclaimer of warranty appears in all copies.
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