Electronegativity Equalization Method: Parameterization and Validation for Large Sets of Organic, Organohalogene and Organometal Molecule

The Electronegativity Equalization Method (EEM) is a fast approach for chargecalculation. A challenging part of the EEM is the parameterization, which is performedusing ab initio charges obtained for a set of molecules. The goal of our work was to performthe EEM parameterization for selected sets of organic, organohalogen and organometalmolecules. We have performed the most robust parameterization published so far. The EEMparameterization was based on 12 training sets selected from a database of predicted 3Dstructures (NCI DIS) and from a database of crystallographic structures (CSD). Each setcontained from 2000 to 6000 molecules. We have shown that the number of molecules inthe training set is very important for quality of the parameters. We have improved EEMparameters (STO-3G MPA charges) for elements that were already parameterized,specifically: C, O, N, H, S, F and Cl. The new parameters provide more accurate chargesthan those published previously. We have also developed new parameters for elements thatwere not parameterized yet, specifically for Br, I, Fe and Zn. We have also performedcrossover validation of all obtained parameters using all training sets that included relevantelements and confirmed that calculated parameters provide accurate charges

The bio.tools registry of software tools and data resources for the life sciences

Bioinformaticians and biologists rely increasingly upon workflows for the flexible utilization of the many life science tools that are needed to optimally convert data into knowledge. We outline a pan-European enterprise to provide a catalogue () of tools and databases that can be used in these workflows. bio.tools not only lists where to find resources, but also provides a wide variety of practical information