Choosing the constraints

GROMACS version: 2020.4

Hi,
my name is Kasra and I am using the 2020.4 Gromacs version to simulate peptides. I decided to use charmm36-Aug2019 as a forcefield. I do not know which constraints(H_bonds or all_bonds) I should choose for my simulations. I want to know if the charmm36-Aug2019 is parameterized for H_bonds or all_bonds and if there is any solid reference for that.

Thank you in advance for your help,
Kasra

The CHARMM force field is designed for use with bonds to H constrained, not all bonds.

Please use the most up-to-date force field port, dated July 2022.

Thank you
I am already in the middle of my project and cannot change it to the up-to-date one.

can you please give me a reliable reference for this H-constrained design of CHARMM?

The constraint convention has been true since the late 1990s, when the CHARMM22 all-atom parameter set was introduced.