hydrogen bond term of force fields

Dear LAMMPS users,
I read that force fields won’t use an explicit term for hydrogen bonds, but how they would consider its effects without defining terms and parameters for that?
Best

This is not true: many potentials have an explicit term for describing hydrogen bonds, e.g., COMPASS, PCFF/PCFF+, and ReaxFF.

Ray

This is not true: many potentials have an explicit term for describing
hydrogen bonds, e.g., COMPASS, PCFF/PCFF+, and ReaxFF.

​...and even if there is no explicit hydrogen bond term, they are often
well represented due to how (partial) charges and​ vdw interactions are
placed. just look at 3-site water potentials. there are studies about
hydrogen bond patterns in water from classical potentials that date back
more than 40 years. after all, one can argue that hydrogen bonds are not
that much of a distinct interaction (as compared to covalent bonds), but a
side effect of hydrogen atoms having a small and easily displaceable
electron hull which will expose the proton in polar covalent bond more to
electron-rich areas and the small radius will let it get closer, so that
there can be a much stronger coulomb interaction as with larger atoms
(which also will have closed inner electron shells). within that line of
arguing, hydrogen bonds are just a logical consequence of geometry and
charge distribution.

axel.

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