**Grid_Types***enumerated choices: {Hydrophobic/Polar|Acid/Base}*- The Grid_Types parameter allows the specification of the
information to be calculated by the HintGrid command. Alternately,
you can calculate a map where the positive grid values represent
hydrophobic regions and negative grid values represent polar
regions or a map where the polar information has been categorized
into acidic regions and polar regions (at the expense of the
hydrophobic information which is lost). If all three types of
infomation are desired, you will have to run two HINT map
calculations. The available Grid Type options are:
- Hydrophobic/Polar where positive map values represent hydrophobic
regions of space and negative map values represent polar regions
of space.
- Acid/Base where positive map values represent acidic regions of
space and negative map values represent basic regions of space.
Note that this option requires the selection of an Acid Base
Definition.
**AcidBase Definition***enumerated choices: {Coulombic|Bronsted|Lewis}*- The AcidBase Definition parameter specifies what model for
acids and bases will be used by HINT if Grid_Type is set to
Acid/Base. These definitions are static; they are based on
the CVFF potential types and are not dynamically reevaluated.
Three models are available as options:
- Coulombic is a formal charge-based model. Atoms with formal
positive charges are considered to be acids and atoms with
formal negative charges are considered to be bases.
- Bronsted uses the Bronsted-Lowry theory of acids and bases.
An acid is a proton donor while a base is a proton acceptor.
- Lewis uses the Lewis theory of acids and bases. An acid is
an electron pair acceptor and a base is an electron pair
donor.
**Cut-Off Radius***real number*- The Cut-Off Radius parameter represents a method to reduce
calculation time for HINT calculations. If the distance
between two atoms (for HintTable calculations) or between
a grid point and an atom (for HintGrid calculations) exceeds the
cutoff-radius that interaction is ignored. Cut-Off Radius
values of greater than 6.0 Angstroms appear to have minimal
effect on the calculation quality but can save considerable
calculation time.
**Volume_Averaging***on/off*- Turning On the Volume_Averaging parameter produces smoother
HINT maps, but at a cost of approximately an eight-fold
increase in calculation time. The algorithm surrounds each
actual grid point with a box whose corners are at (+/-) 1/3
grid spacing along each cartesian axis. The map is evaluated
for each corner of the box and the resulting values averaged
to yield the map value at the original grid point.
**Van der Waals Limit***real number*- The Van der Waals Limit parameter allows limited user control
of the HINT Van der Waals radii set. The Van der Waals Limit
is a multiplicative factor (default = 1.00) that adjusts the
predefined radii set. A value of less than 1 would allow
more "bump" between atoms, while a value greater than one
would allow less.
**Inside Mol Cutoff***on/off*- The Inside Mol Cutoff parameter specifies whether grid points inside the Van der Waals radius of any atom are to be set to predefined constant values.
**Lo Limit***real number*- The Lo Limit parameter is the constant that will be assigned to negative-valued grid points inside the Van der Waals radius of any atom if Inside Mol Cutoff is set to On.
**Hi Limit***real number*- The Hi Limit parameter is the constant that will be assigned to positive-valued grid points inside the Van der Waals radius of any atom if Inside Mol Cutoff is set to On.