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MCCCS Towhee (ClayFF)

 

 

Overview
    This section covers the ClayFF force field as it is implemented into the towhee_ff_ClayFF file in the ForceFields directory. All of the Towhee atom types for the ClayFF force field are listed, along with a short description of their meanings. Any discrepencies (especially typos) from the published force field values are the sole responsibility of Marcus G. Martin, and I welcome feedback on how this implementation compares with other programs.

     

References for ClayFF ClayFF in Towhee
    The official force field name for these parameters is 'ClayFF'. Here I list all of the ClayFF atom names for use in the towhee_input file, along with a brief description. Please note that the capitalization and spacing pattern is important and must be followed exactly as listed here.
    • 'h*' : water hydrogen
    • 'ho' : hydroxyl hydrogen
    • 'o*' : water oxygen
    • 'oh' : hydroxyl oxygen
    • 'ob' : bridging oxygen
    • 'obos' : bridging oxygen with octahedral substitution
    • 'obts' : bridging oxygen with tetrahedral substitution
    • 'obss' : bridging oxygen with double substitution
    • 'ohs' : hydroxyl oxygen with substitution
    • 'st' : tetrahedral silicon
    • 'ao' : octahedral aluminum
    • 'at' : tetrahedral aluminum
    • 'mgo' : octahedral magnesium
    • 'mgh' : hydroxide magnesium
    • 'cao' : octahedral calcium
    • 'cah' : hydroxide calcium
    • 'feo' : octahedral iron
    • 'lio' : octahedral lithium
    • 'Na' : aqueous sodium ion
    • 'K' : aqueous potassium ion
    • 'Cs' : aqueous cesium ion
    • 'Ca' : aqueous calcium ion
    • 'Ba' : aqueous barium ion
    • 'Cl' : aqueous chloride ion
Coulombic Interactions
    This force field uses point charges on atomic centers. Here we list suggested charges for each of the atom types in this force field.
    • 'h*' : 0.4100
    • 'ho' : 0.4250
    • 'o*' : -0.8200
    • 'oh' : -0.9500
    • 'ob' : -1.0500
    • 'obos' : -1.1808
    • 'obts' : -1.1688
    • 'obss' : -1.2996
    • 'ohs' : -1.0808
    • 'st' : 2.1000
    • 'ao' : 1.5750
    • 'at' : 1.5750
    • 'mgo' : 1.3600
    • 'mgh' : 1.0500
    • 'cao' : 1.3600
    • 'cah' : 1.0500
    • 'feo' : 1.5750
    • 'lio' : 0.5250
    • 'Na' : 1.0
    • 'K' : 1.0
    • 'Cs' : 1.0
    • 'Ca' : 2.0
    • 'Ba' : 2.0
    • 'Cl' : -1.0
Improper torsions
    There are no improper torsions in this force field.
Proteins
    This forcefield is not designed for proteins.
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Send comments to: Marcus G. Martin
Last updated: September 07, 2005