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I don't know if this could be the issue, but are you sure that after
the energy minimization step you are using the .gro file you've
obtained?<br>
<br>
I'm telling you this because once I forgot to put it on the
following nvt equilibration: grompp -f nvt.mdp -c <b>em.gro</b> -p
topol.top -o nvt.tpr and I got the same error.<br>
<br>
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