From: Axel Kohlmeyer (akohlmey_at_gmail.com)
Date: Fri Mar 25 2011 - 08:17:05 CDT
On Fri, Mar 25, 2011 at 4:44 AM, Ajasja Ljubetič
<ajasja.ljubetic_at_gmail.com> wrote:
> Dear all,
> I too would like to know if this is possible (I'd like to make an endless
> alpha-helix)
> Any suggestion welcome.
adding the bond should not be a problem with the .psf file.
i would not manually manipulate the .psf file with a text editor,
since that is rather error prone. you can define individual bonds
easily in VMD with: topo addbond <atom 1> <atom 2>
you have to be very careful with the simulation cell definition,
since that has now an impact on how much that bond is
stretched, and thus starting with a minimization is probably
a very good idea.
i don't know about NAMD, but i use LAMMPS a lot
these days and this method works perfectly there.
cheers,
axel.
> Best regards,
> Ajasja
> 2011/3/25 王棽 <corarbor_at_163.com>
>>
>> Dear all:
>> I am writing the topology .psf file for an infinite large solid wall, I
>> have to address the bond between the atoms at the boundary of the cell box
>> so as to exclude the non-bonded interaction between these atoms. I have kept
>> precise margin space for the box so as to keep the right distance for the
>> atoms at the boundary. The serial indices for the bonded atoms, one of which
>> is at the right end of the box and the other at the left end, were put in
>> the !NBOND part of the .psf file. However, I got a "Bad global exclusion
>> count errors" when I ran NAMD. I read the NAMD troubleshooting page about
>> this error message. How can I, then, define the bonds between the atoms
>> across the boundary at the psf file?
>> Cheers.
>> Wang Shen
>>
>>
>
>
-- Dr. Axel Kohlmeyer akohlmey_at_gmail.com http://goo.gl/1wk0 Institute for Computational Molecular Science Temple University, Philadelphia PA, USA.
This archive was generated by hypermail 2.1.6 : Mon Dec 31 2012 - 23:19:59 CST