Abstract: Molecules are represented as one dimensional strings of atoms having a linear position and a width. One dimensional representations are compared to assess the likelihood of similarity in chemical behavior.

Abstract: Methods and systems for generating pharmacophore models are characterized both by molecular features that are present in the model and features that are defined as absent. Thus, models can be developed that take into account features such as steric bulk that inhibit activity for a specified target as well as features such as functional groups that promote activity. Features that inhibit activity can be identified by comparing known active molecules with known inactive molecules. Features that are present in the inactive molecules but absent in the active molecules can be defined in a pharmacophore model.

Abstract: Methods and systems for generating pharmacophore models are characterized both by molecular features that are present in the model and features that are defined as absent. Thus, models can be developed that take into account features such as steric bulk that inhibit activity for a specified target as well as features such as functional groups that promote activity. Features that inhibit activity can be identified by comparing known active molecules with known inactive molecules. Features that are present in the inactive molecules but absent in the active molecules can be defined in a pharmacophore model.

Abstract: Methods and systems of predicting binding affinity between a ligand and a receptor. In one embodiment, the predicted binding affinity (pKj) is determined by at least using a formula pKj=C0+C1*vdW+C2*Att_pol+C3*(Att_pol*Att_pol+Rep_pol*Rep_pol). vdW represents the van der Waals interaction energy between the ligand and the receptor. Att_pol represents the surface area of the ligand forming complimentary polar interactions with the receptor. Rep_pol represents the surface area of the ligand forming uncomplimentary polar interactions with the receptor. An improved process of calculating linear interpolation of grid-based vdW energy. A first non-linear function is transformed into a less non-linear second non-linear function to reduce the error in linear interpolation. A trilinear interpolation process is applied to the second non-linear function. The value obtained is reverse transformed to produce an estimated vdW energy.

Abstract: Molecules are represented as one dimensional strings of atoms having a linear position and a width. One dimensional representations are compared to assess the likelihood of similarity in chemical behavior.

Abstract: Molecular modeling is performed using atomic parameters which include an anisotropic dipole polarizability tensor. Permanent atomic multipole parameters may also be included in the model. Energy evaluations including contributions from polarization energy and multipole interactions may be conducted which are useful in characterizing molecular properties for drug discovery, materials evaluation, and other applications.

Abstract: This application discloses methods and systems of predicting binding affinity between a ligand and a receptor. In one embodiment, the predicted binding affinity (pKi) is determined by at least using a formula pKi=C0+C1*vdW+C2*Att_pol+C3*(Att_pol*Att_pol+Rep_pol*Rep_pol). vdW represents the van der Waals interaction energy between the ligand and the receptor. Att_pol represents the surface area of the ligand forming complimentary polar interactions with the receptor. Rep_pol represents the surface area of the ligand forming uncomplimentary polar interactions with the receptor. This application also discloses an improved process of calculating linear interpolation of grid-based vdW energy. A first non-linear function is transformed into a less non-linear second non-linear function to reduce the error in linear interpolation. A trilinear interpolation process is applied to the second non-linear function. The value obtained is reverse transformed to produce an estimated vdW energy.