Hi all,<br><br>In addition to modifying atomic charges to the .itp file generated by PRODRG, I also want to change the vdw C12 and C6 parameters of selected 1-4 LJ interactions and modify some 1-5 LJ interactions (or any non-bonded LJ interactions) with the vdw C12 and C6 parameters I prefer.<br>
<br>So should I just make changes to the [ pairs ] section of the .itp file? For example, change<br><br>; ai aj fu c0, c1, ...<br> 1 4 1 <br><br>to<br><br>; ai aj fu c0, c1, ...<br>
1 4 1 0.004724 1.84e-6 <br>
<br>How can I make sure it will override the parameters in the [ pairtypes ] section of the ffnonbonded.itp file? And I should make these values (c0 for C6, c1 for C12) in accordance with the units in [ pairtypes ] section, right?<br>
<br>Moreover, I want to change some dihedral parameters. But I saw the .itp file generated by PRODRG as something like<br><br>[ dihedrals ]<br>; ai aj ak al fu c0, c1, m, ...<br>10 5 4 3 1 0.0 5.9 3 0.0 5.9 3 <br>
<br>so 0.0 is the phase shift, 5.9 is the force constant, 3 is the multiplicity, but why these values appeared twice in a row? When I modify them, should I also write them twice as this format? Will it override dihedral parameters that are already in the ffbonded.itp file?<br>
<br>Thanks very much,<br><br>Yun<br><br><br><br>