These groups are radical corrections to the H bonding 'A' value.
We use them after we calculate solvation thermo for a saturated
structure that we made by saturating radicals with hydrogens.

Radical groups were added for all Platts groups that have an A value,
if they'd come about by saturating with H.

For some reason, there was no data for this group despite there being a Platts group. Allows ammonia unit test to pass.