Re: CCL:Paking in the unit cell

[<woods #*at*# draco.pmmp.uic.edu>]

 Alexandre N. Sobolev wrote:
 >
 > >
 > > Hi
 > >    Along these same lines, I am seeking a program that will allow
 > > one to
 > > build a lattice of molecules by inputting one or several different
 > > molecular files as well as the unit cell dimensions.  I currently
 > > have a
 > > routine called bcell that will make a lattice of multiple copies of
 > > the
 > > SAME molecule file, but I need a routine that will allow a lattice
 > > to be
 > > built which will contain multiple copies of one molecule in the
 > > lattice,
 > > as well as ONE that is different.
 > >
 > >   Anyone have any suggestions?
 > >
 > > Richard
 Hi-
     Let me clarify what I need as I think there may be a
 misunderstanding here.  I am attempting to build a mono/bilayer of
 phospholipids for an MD simulation.  I wish to have 16/32 copies of the
 same molecule aligned in space using the unit cell dimensions of a
 single crystal.  What I want to do is selectively introduce a double
 bond in ONE of the phospholipids.  Thus, I want 15/31 saturated lipids
 and 1 unsaturated lipid.  The routine that I have will allow me to
 assemble multiple copies of ONE file, not two, which is what I need.
 I used a program called Chemlab to build my original lipid, and i sue it
 to introduce the unsaturation in my lipid, but I cannot use it to edit a
 mono/bilayer, as it only handles 999 atoms.  I can't modify Chemlab as
 we don't have access to the code.
 Any suggestions?
 Richard