Re: Multiplicity of Parameters

From: Philip Peartree (
Date: Thu Aug 09 2007 - 17:59:26 CDT

Hi Peter,

I generated the psf using the VMD psf gen tool (the graphical one, not the
commandline version) and the topology file is one of my own making
Charmm27 but with a few additional residues (I'm simulating a quinoprotein,
which contains a modified tryptophan) I'm assuming that the problem is with
that residue, but the thing puzzling me is that it worked fine in c31 itself.

Philip Peartree

Quoting Peter Freddolino <>:

> Hi Philip,
> just to verify, could you please let us know how you generated your psf?
> And which topology file are you using?
> Best,
> Peter
> Philip Peartree wrote:
>> Dear All
>> Upon running (an albeit) basic simulation (Minimisation, I received the
>> following error:
>> FATAL ERROR: Multiplicity of Paramters for diehedral bond CA CA CA CA of 1
>> exceeded
>> I am aware that several messages of this type have been posted to
>> this list, but
>> none have fully detailed a positive outcome. From what I have read of other
>> messages, this is something to do with a wrongly typed bond somewhere in the
>> topology file (I am using a Charmm type topology). However, this
>> topology/parameter set worked fine in Charmm31 (I have decided to
>> start running
>> in NAMD since it was taking about 3.5 months to run a 10 ns simulation!!)
>> What should I do about correcting this, since the bonds are
>> correctly defined in
>> the topology (as far as I know)
>> Philip Peartree
>> Sutcliffe Group
>> University of Manchester

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