<font color="#000099">Dear Gromacs users,<br><br>Im new to gromacs and I'm following a tutorial (<a href="http://nmr.chem.uu.nl/~tsjerk/course/molmod/">http://nmr.chem.uu.nl/~tsjerk/course/molmod/</a>). Unfortunately, the tutorials doesn't say anything about how to update the topology file after using 'genion' to replace a few water molecules with ions. <br>
I manually edited the topology file and updated the number of water molecules and added the number of ions:<br><br>[ molecules ]<br>; Compound #mols<br>Protein_chain_A 1<br>SOL 7791<br>Na+ 26<br>
Cl- 23<br><br>But then when I tried to preprocess the structure with grompp, I got an error:<br><br>Fatal error:<br>No such moleculetype Na+<br><br>Any help will be greatly appreciated!<br><br clear="all"></font><span style="color:rgb(0, 0, 153)">Jose M. Borreguero</span><br>
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