[gmx-users] Why so many energy minimization and position restrained simulation steps?

[Peggy Yao]

Hi,

I am new to Gromacs. I am following this tutorial:
http://www.nmr.chem.uu.nl/~abonvin/tutorials/MD-Data/index.html. My
question is: why it has multiple steps of energy minimization and
position restrained simulation? Is that a common practice? What's the
key difference among these steps?

Thanks!

Peggy