A High-Resolution Shape-Fragment MEDLA Database for Toxicological Shape Analysis of PAHs

A new, high-resolution shape-fragment database has been developed for computing ab initio quality molecular electron densities for polyaromatic hydrocarbons (PAHs) which play a significant role as toxicants in the environment. Using the new PAH electron density fragment database and the Molecular Electron Density Lego Assembler (MEDLA) method, one can generate detailed and reliable electron densities for virtually any of the PAH molecules. Accurate electron density shape representations for these molecules is essential in the study of detailed shape-toxicity correlations. One of our goals is to investigate the potential of detailed molecular shape analysis as a predictive tool in toxicological risk assessment. In this study we report the results of the first phase of the study:  the construction and testing of a high quality shape-fragment database for PAHs.