Intramolecular (extra) electrostatic interactions

GROMACS version: 2020.1 or newer
GROMACS modification: No

Dear,

According to the manual, it should be possible to set
the intramolecular pair interactions:
“Extra Lennard-Jones and electrostatic interactions”.
It is clear to me how to deal with LJ interactions via
[ pairs ] and [ pairtypes ], but I did not understand
how to define the intramolecular pair-specific electrostatic interactions,
meaning not just scalling e.g. 1-4 interactions using fudgeQQ but really specifically
for any wanted atom pair (or pairtype).

1, Would you point me to an example of that?
2, Is it possible to define for a given intramolecular atom pair(type)
both LJ parameters and electrostatics?

Thank you!
Best regards,
Jiri

Dear all,

I will try to ask once more shortly:

Is there a way to modify the intramolecular electrostatic interaction in more specific way than by using the fudgeQQ in [ defaults ]?

It would be important to know for my plans.
Thank you,
Jiri