OpenEye Scientific is now part of Cadence

2016-10 | QUACPAC v1.7.0 Released

2016-10 | QUACPAC v1.7.0 Released

OpenEye is pleased to announce the release of QUACPAC v1.7.0. This upgrade adds a number of features and fixes several bugs.


Tautomers is a program used for canonicalizing and/or enumerating the tautomeric forms of a small molecule. Tautomers now outputs a low-energy, medicinally relevant, “reasonable” tautomer. The depictions below are a useful guide for recognizing how tautomers are favored as reasonable:

  • Conversion of carboxylates to diols and nitros to di-hydroxy amines is not favored.

    disfavored and favored
  • Generation of unnecessary, non-dative, formal charges is not favored.

    disfavored and favoreddisfavored and favored
  • Exocyclic bonds adjacent to aromatic rings are accounted for.

    disfavored and favored
  • Priority is given to aliphatic double-bond positions.

    disfavored and favored

AM1BCC ELF10 method has been added to molcharge for applying partial charges to a molecule, allowing up to 10 diverse conformers to be selected from conformers having the Electrostatically Least-interacting Functional groups (ELF). These conformers are then charged with the AM1BCCSym method and the charge sets are averaged to come up with a single charge set that is applied to all conformers.
Tautomers, molcharge, pkatyper, and fixpka will label unnamed input molecules as output_1, output_2, etc.

  • Support for Ubuntu 14 has been added.
  • Support for RedHat 7 has been added.
  • Support for Mac OS X 10.10 and 10.11 has been added.
  • Mac OS X 10.7 and 10.8 are no longer supported.
  • SuSe 11 is no longer supported.

QUACPAC is now available for download. Existing licenses will continue to work, but if a new license is required, contact your account manager or email


About OpenEye Scientific Software
OpenEye Scientific Software Inc. is a privately held company headquartered in Santa Fe, NM, with offices in Boston, Cologne, Strasbourg, and Tokyo. It was founded in 1997 to develop large-scale molecular modeling applications and toolkits. Primarily aimed towards drug discovery and design, areas of application include:

The software is designed for scientific rigor, as well as speed, scalability and platform independence. OpenEye makes most of its technology available as toolkits - programming libraries suitable for custom development. OpenEye software typically is distributable across multiple processors and runs on Linux, Windows and Mac OS X.

For additional information
Jeffrey Grandy
VP  Sales