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 nb initio quality molecular electron densities for polyaroma tic 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 an y of the PAH molecules. Accurate electron density shape representation s for these molecules is essential in the study of detailed shape-toxi city correlations. One of our goals is to investigate the potential of detailed molecular shape analysis as a predictive tool in toxicologic al risk assessment. In this study we report the results of the first p hase of the study: the construction and testing of a high quality shap e-fragment database for PAHs.