SMIRNOFF: definition of vacuum dielectric constant?

[mrshirts]

So, AMBER electrostatics assume a slightly old definition of the dielectric constant. Does this need to be specified as well?

See https://link.springer.com/article/10.1007%2Fs10822-016-9977-1 for a discussion of the issue and the differences between different programs.

One can sort of work around it since AMBER .prmtop actually defines the charges as sqrt(vacuum dielectric constant)*charge, so one can alter the charge here to give the same electrostatic energy as in another system.

[mrshirts]

Bumping the questions if the dielectric constant needs to be defined.