  Eumelanin is regarded to be an attractive candidate material for biomedical
applications. Despite many theoretical studies exploring the structure of
eumelanin, an exact mapping of the energetic landscape of the very large phase
space of eumelanin is still elusive. In this work, we implement a piecewise
Ising Model to predict formation enthalpies of Eumelanin single and double
tetramers, and demonstrate its superior predictive and generalizable
capabilities. We believe this model will prove very useful in theoretically
characterizing the many unique properties attributed to its disorder. The
modular nature of the predictive Ising model built up in this work is
well-suited for analysis and characterization of a larger phase space of
eumelanin polymers, including hexamers and octomers, as well as larger stacked
structures, such as potential triple and quadruple eumelanin tetramers.
Absorbance data can be incorporated with population-wide predictions of polymer
abundance to produce weighted-average predictions of broadband absorbance of
bulk eumelanin.
