Charge constraints
PsiRESP offers two forms of constraints:
a ChargeSumConstraint
and
a ChargeEquivalenceConstraint
.
A ChargeSumConstraint
constrains
one or a group of atoms to a single charge. For example, this is very helpful
if you are parametrizing a residue in a large molecule, and you need
the cap atoms to sum to 0.
A ChargeEquivalenceConstraint
constrains every atom specified to the same charge. For example, you could
manually constrain all hydrogens around a single carbon to the same charge.
For this reason, a ChargeEquivalenceConstraint
must contain at least two atoms.
All of these are contained in
ChargeConstraintOptions
.
ChargeConstraintOptions are passed to a Job
.
As ChargeConstraintOptions may contain charge constraints for molecules
that are not considered in the Job
, the job will
create MoleculeChargeConstraints
to work on.
Users should typically not interact with
MoleculeChargeConstraints
themselves, but let the Job
handle it.
MoleculeChargeConstraints
contains helper
methods such as adding symmetry constraints for sp3 hydrogens.