Hi,

the number of iterations may vary, but the two main aspects you have to be careful is the space between lipid headgroups: not too close to get repulsions but not too far to allow water insertion into the hydrophobic core.

Probably 0.65-0.80 A will be a decent range to start with, because the major adjustments will be done in the MD steps.

All the answers you need are available here on this website

https://manual.gromacs.org/documentation/2019/reference-manual/functions/restraints.html

You can choose to use gmembed from the gromacs package, it's much simpler...

Thanks Dr. Bezerra.

Any questions can contact Zeeshan Zafar