D Ligand-Based Virtual Screening

Similarly to ROCS, the Cresset FieldScreen approach [31, 32] considers multiple 3D conformations. These are generated with a force field based on nonatom-centered extended electron distribution charges (XED). From the interaction energy with molecular probes, four 3D field properties are then calculated steric, hydrophobic. 

The field prints are calculated from the distance matrix of field points for each conformer. The remaining top ranking 50% of the database is then subjected to similarity assessment via 3D field points, the so-called clique refinement. In the last step, the top ranking 20% from the clique refinement are reranked via an optimized alignment. 

In EON [33], also from OpenEye Scientific Software, the Poisson-Boltzmann equation is solved to calculate the electrostatic potential on the nodes of a 3 D grid constructed around a molecule. The molecule has MMEE94 nuclei-centered charges assigned. The OpenEye Electrostatic Tanimoto (OEET) similarity is given by 

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