Subject: Request: DFT methods for silica nanoparticles

From: Wai-To Chan <chan /a\ curl.gkcl.yorku.ca>
Date: Sun, 20 Feb 2005 04:40:23 -0500 (EST)

There is this method "Promolecule electron density isosurface" 
 described in 

 "Molecular surfaces from the promolecule: A comparison with 
 Hartree-Fock Ab Initio electron density surfaces" 
Mitchell and Spackman, J comp chem, vol 21 933-92 (2000) 

  that may perhaps suit your need. This paper reports isosurfaces of 
macromolecules as big a few thousand A^3. According to this paper this 
type of electron density isosurface is easy to calculate and compares 
well with results obtained from ab initio methods. 

Wai-To Chan

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Hello,

I'm interested in simulating the detailed charge density distribution on 
the surface of growing silica nanoparticles (~ 3-10 nm). I'm hoping that 
this will be possible using DFT/pseudopotential approaches: the 
potential number of atoms considered in such a simulation is quite high, 
I know. I would be very grateful if anyone on this list could advise me 
on the best techniques for such simulations.

I would prefer not to have to move to using empirical potentials just to 
make the calculation tractable. My main interest is having a reliable 
charge density distribution, with a view to investigations of the 
topology of the chage density distribution on the surface of the 
nanoparticles.

I may also need to consider surface reconstructions and atomic 
substitutions in the future, so techniques that might allow a realistic 
model of these phenomena are also of interest to me.

Any advice would be very gratefully recieved,

Steve Kirk