Define position restraints in mdp

GROMACS version: 2020
GROMACS modification: Yes/No
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Dear GROMACS user
How to define the position restrain constant in the .mdp file? For example, I want to run NVT simulation at 100 kcal/mol so I chose -DPOSRES to FC=418 KJ which is equal to 100kcal and I also changed the to include -DPOSRES_FC is that correct? I am not sure if this method is correct or no

Thank you

; Preprocessing
define = -DPOSRES -DPOSRES_FC=418 ; position restrain the protein

; Run Control
integrator = md ; leap-frog integrator
dt = 0.002 ; [ps] time step for integration 2fs
nsteps = 10000 ; 2 * 10000 = 20 ps

If your topology makes use of a keyword POSRES_FC, then yes, this is correct.