QUACPAC offers everything necessary to do charges well. As the chemistry of molecular interactions is a matter of shape and electrostatics, accurate or at least consistent charge representation is critical in drug design. However, even the best charge models are of limited value if protonation states are wrong.
QUACPAC provides pKa and tautomer enumeration in order to get correct protonation states. It also offers multiple partial charge models (including MMFF94 [1], AM1-BCC [2], and AMBER [3]) that cover a range of speed and quality in order to allow appropriate charging for every end use.
QUACPAC's approach to tautomeric enumeration is to provide multiple tautomeric states rather than one "correct" tautomer. Subsequent downstream processes are then used to identify the appropriate tautomeric form.
Electrostatic potential around a collagenase inhibitor when it is charged using the AM1-BCC and Gasteiger models. Appropriate charging is critical for accurate calculations and meaningful visualizations.
Graphs comparing the accuracy of the AM1-BCC and Gasteiger charge models for reproducing experimental measurements.
The Cheminformatics suite of toolkits provides the core foundation upon which all of the OpenEye applications and remaining toolkits are built. The Cheminformatics suite is a collection of seven individual yet interdependent toolkits that are described in the table below.
The Modeling suite of toolkits provides the core functionality underlying OpenEye's defining principle that shape & electrostatics are the two fundamental descriptors determining intermolecular interactions. Many of the toolkits in the Modeling suite are directly associated with specific OpenEye applications and can therefore be used to create new or extend existing functionality associated with those applications.