
               -----------------------------------------------
               PARAMS Directory for the TINKER Program Package
               -----------------------------------------------

      This directory contains the force field parameter sets distributed
      with the TINKER package, implementing a selection of widely-used
      literature force fields as well as the TINKER force field now
      under development in the Ponder lab. A brief description of each
      parameter set is provided below:

      amber      AMBER-95 parameters for proteins. The nucleic acid
                 parameters are not implemented yet. Note that with
                 their AMBER-95, the Kollman group has devised separate,
                 fully independent electrostatic parameters for each of
                 the common N- and C-terminal residues. At present, the
                 terminal residue charges are not set correctly by the
                 parameter file and must be set manually in a keyfile.

      blank      An empty parameter file which can be added to
                 a keyfile when the user intends to explicitly supply
                 all parameters via the keyfile.

#     charmm     CHARMM22b parameters for proteins. Most of the
#                nucleic acid, lipid and small model compound
#                parameters are not yet implemented.
#
# (This file was removed starting from TINKER 3.5mn2)

      emr        Reduced EMR model of Pappu, Schneller and Weaver.
                 Only a few residue types have been implemented.

      encad      ENCAD parameters for proteins and nucleic acids
                 (still in preparation).

      hoch       Simple NMR-NOE force field of Hoch and Stern.

      merck      Preliminary MMFF vdw parameters from Halgren.

      mm2        Full MM2(91) parameters including pi-systems.
                 The anomeric and electronegativity correction terms
                 are not implemented.

      mm3        Full MM3(96) parameters including pi-systems.
                 The anomeric, electronegativity, Bohlmann and hydrogen
                 bond directionality correction terms are not implemented

      mm3pro     Protein-only version of the MM3 parameters.

      mmff       MMFF94 parameters (still in preparation).

      mmffpro    Protein-only version of the MMFF94 parameters
                 (still in preparation).

      opls       Complete AMBER/OPLS United-Atom parameters for proteins
                 and many classes of organic molecules. Explicit hydrogens
                 on polar atoms and aromatic carbons.

      oplsaa     OPLS All-Atom parameters for proteins and many general
                 classes of organic molecules (still in preparation).

      smooth     Parameters for use with the potential energy
                 smoothing methods. Largely adapted largely from
                 OPLS modifications to the vdw and improper torsion
                 terms.

      tinker     Protein-only parameters for the TINKER force
                 field with multipole values of Dudek and Ponder.
                 The current file contains all the multipole values,
                 but many other terms are still under development.

      water      The current TINKER water parameters for a
                 polarizable multipole electrostatics model. This
                 model is equal or better to the best available water
                 models for many bulk and cluster properties.

