Coarse-Grained Models for Constant pH Simulations of Carboxylic Acids

Naeyma N Islam; Arjun Sharma; Gaurav Gyawali; Revati Kumar; Steven W Rick

doi:10.1021/acs.jctc.9b00159

Coarse-Grained Models for Constant pH Simulations of Carboxylic Acids

J Chem Theory Comput. 2019 Aug 13;15(8):4623-4631. doi: 10.1021/acs.jctc.9b00159. Epub 2019 Jul 2.

Authors

Naeyma N Islam¹, Arjun Sharma¹, Gaurav Gyawali¹, Revati Kumar², Steven W Rick¹

Affiliations

¹ Department of Chemistry , University of New Orleans , New Orleans , Louisiana 70148 , United States.
² Department of Chemistry , Louisiana State University , Baton Rouge , Louisiana 70808 , United States.

PMID: 31265273
DOI: 10.1021/acs.jctc.9b00159

Abstract

A model for carboxylic acids, in both the protonated and deprotonated states, is developed in which hydrogen interaction sites are not used and all interactions are short-ranged. A method for constant pH simulations, which exploits these features of the model, is developed. The constant pH method samples protonation states by making discrete Monte Carlo steps and is able to efficiently move between states in two steps. The method is applied to the polymer poly(methacrylic acid), a pH-responsive polymer that undergoes structural changes as a function of pH. The model is able to reproduce the structural changes induced by pH.