MCCCS Towhee (DACNIS United Atom)



    This section covers the DACNIS United Atom force field as it is implemented into the towhee_ff_DACNIS-UA file in the ForceFields directory. All of the Towhee atom types for the DACNIS United Atom force field are listed, along with a short description of their meanings. DACNIS-UA is a little force field I created for performing some simulations of methane and ethane adsorption in silicalite using a cut-and-shift potential. This was useful as the main application of the force field was computing the transport of methane through silicalite using the dual control volume grand canoical molecular dynamics code Ladera. Note that DACNIS United Atom is a Lennard-Jones (12-6) force field and can only be combined with other Lennard-Jones (12-6) force fields. I welcome feedback on how this implementation compares with other programs (assuming anyone else has ever bothered to implement this force field).


References for DACNIS-UA DACNIS-UA in Towhee
    The official force field name for DACNIS United Atom in Towhee is 'DACNIS-UA'. Here I list all of the DACNIS atom names for use in the towhee_input file, along with a brief description. I created these atom names in order to work with the molecule assembler. DACNIS-UA is a united atom force field which lumps atoms together. There are only three different groups at the moment. Note that the Ozeo group is designed for a fixed conformation of silicalite so it has no bonded interactions. Please note that the capitalization and spacing pattern is important and must be followed exactly as listed here.
    • 'CH4sp3' : methane
    • 'CH3sp3' : sp3 non-aromatic carbon bonded to three hydrogens and one heavy atom
    • 'Ozeo' : oxygen groups in silicalite.
Coulombic interactions
    There are currently no coulombic interactions in the DACNIS-UA force field.
Improper torsions
    DACNIS-UA does not utilize improper torsions.
    DACNIS-UA does not have all of the groups needed for protein simulations.
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Send comments to: Marcus G. Martin
Last updated: September 07, 2005