Both of these type sites can form hydrogen bonds with water.
They have little to no capacity to form hydrogen bonds.
These bases form three hydrogen bonds between each other and are therefore particularly strong.
Some force fields also include explicit terms for hydrogen bonds.
The typical length of a hydrogen bond in water is 197 pm.
It is held with hydrogen bonds, which are otherwise weak.
The figure below shows the calculated positions of hydrogen bonds.
But when acid water fills their hands, they cannot hydrogen bond as well.
"A hydrogen bond," he has said to me, often enough to make it irritating.
On the other hand, all those hydrogen bonds represent a chemical interaction.