TanimotoCombo, from OpenEye Scientific, is a normalized method of measuring geometric similarity between molecules. It is the sum of ShapeTanimoto, a measure of overall spatial overlap between two molecules, and ColorTanimoto, a measure of spatial overlap of specific functional groups between two molecules, both of which are also metrics from OpenEye. Tanimoto-Combo values between two conformers range between 0 and 2 (it is the sum of two values running from 0 to 1), with 2 being the most similar and 0 being the most different.