MCCCS Towhee (TIP3P)



    This section covers the TIP3P force field for water as it is implemented into the towhee_ff_TIP3P file in the ForceFields directory. All of the Towhee atom types for this force field are listed, along with a short description of their meanings. This is perhaps the most popular water potential of all time and several other force fields use similar parameterizations. TIP3P is a rigid water model that has a Lennard-Jones site on the Oxygen and bare charge sites on the Hydrogens. The Jorgensen group has also parameterized two other water models that utilize additional interaction sites. Please see the TIP4Pand TIP5P web pages for more information about those water models. This water model is suitable for use with any Lennard-Jones forcefield, but is especially well suited for the OPLS family of potentials. Please see the OPLS-ua, OPLS-aa, and OPLS-2001 web pages for more information. Any discrepencies (especially typos) from the published force field values are the sole responsibility of Marcus Martin, and I welcome feedback on how this implementation compares with other programs.


References for TIP3P TIP3P in Towhee
    The official force field name for TIP3P in Towhee is 'TIP3P'. Here I list all of the atom names for use in the towhee_input file, along with a brief description taken from the literature. Please note that the capitalization and spacing pattern is important and must be followed exactly as listed here.
    • 'H' : hydrogen in water
    • 'O' : oxygen in water
Coulombic interactions
    TIP3P uses atom-centered point charges to represent the electrostatic interactions. The 'bond increment' method for assigning charges is implemented for this force field. Please see the inpstyle 2 documentation for further information on enabling this option. Here I list the bond increments for the atom names listed above. The value of the bond increment is added to the first atom listed and subtracted from the second atom listed.
    • H - O: 0.417
Return to the Towhee Capabilities web page


Send comments to: Marcus G. Martin
Last updated: September 07, 2005