Subject: Summery: ionicity of a bond

From: Thomas Nowak <[email-masked]>
Date: Fri, 4 Feb 2000 21:27:06 +0100 (MET)

Dear CCL'er

Last week I have posted a messages to the board. Thanks for all which
have answer my question!
Below is the summury of the posting

Regards

Thomas Nowak 
Martin-Luther Universitaet Halle 
FB Chemie (Merseburg)  
IPC
06099 Halle

email: [email-masked]

The orginal message was:

On Thu, 20 Jan 2000, Thomas Nowak wrote:

> 
> Dear CCLers,
> 
> I want to study various Nd complexes of the type Nd(L)3-olefin with DFT
> calculation. I want to characterize the Nd-olefin bond. The main
> contribution of the bond should be an ionic quadropole interaction. But I
> am looking for a tool to get a quantity of this ionic part and the
> covalent part ( donation from olefin pi-bond to the Nd ). I have tried to
> get the ionic part by an interaction of a point charge with the olefin,
> but because of the ligands I don't know exactly how big this charge must
> be. 
> 
> 
> Thanks in advance, 
> 
> Thomas Nowak 
> Martin-Luther Universitaet Halle 
> FB Chemie (Merseburg)  
> IPC
> 06099 Halle
> 
> email: [email-masked]
> 
> 
> 
> 

 Fred P. Arnold <[email-masked]> wrote:

>It's a cheap-seats way to go, but you may want to look into the current
>version of NBO, since the NRT (natural resonance theory) module breaks
>the
>bonding contributions down into ionic/covalent.  It gives chemically
>reasonable results for hypervalent main-group complexes, but I don't know
>how well it would handle lanthanides.  It certainly gave me enough
>trouble
>with traditional organometallics.
>
>                                                        -fred
>
>"No science has ever made                 Frederick P. Arnold, Jr.  
> more rapid progress in a                 A&HPRC, U. of Chicago     
> shorter time than Chemistry."            5640 S. Ellis Ave             
>        -Martin Heinrich Kloproth, 1791   Chicago, IL 60637 
>

Stefan Fau <[email-masked]> wrote:

>Hi Thomas,
>
>if you are interested in analysing the energetics of a donor-acceptor 
>complex, you might want to use some sort of energy decomposition scheme. 
>
>Since both fragments are so close together, approximating the charge 
>distribution of the NdL3 fragment by a point charge will probably not 
>produce meaningful results. 
>
>The above mentioned scheme is implemented in ADF. There are other energy 
>decomposition schemes, too, but as I said, this is my favourite. If you 
>are interested, contact Dr. Matthias Bickelhaupt ([email-masked]) in 
>Amsterdam, he knows much more.
>
>Stefan
>______________________________________________________________________
>Dr. Stefan Fau                  [email-masked]
>Quantum Theory Project
>University of Florida
>Gainesville FL 32611-8435

and Wannere Chaitanya S. <[email-masked]> wrote:

>Hi Thomas, 
>
>I was also trying to look in to one analogous problem of that kind. Well,
>I am not sure about the tool. But may be GAMESS can give the answer to
>this question by decomposition of the energy in to various components. I
>am still working on this problem. Well, I can tell you 2 papers which
>shall more or less answer the problem you have adressed. The following
>are
>the papers: 
>
>"NATURAL ENERGY DECOMPOSITION ANALYSIS: AN ENERGY PARTITIONING
>PROCEDURE FOR MOLECULAR INTERACTIONS WITH APPLICATION TO WEAK HYDROGEN
>BONDING, STRONG IONIC, AND MODERATE DONOR-ACCEPTOR INTERACTIONS"  by
>Glendening and Streitwieser appeared in J. Chem. Phys.  in
>1994. vol. 100,
>pg 2900.  
>
>This is the latest scheme devised and then before this there was
>a scheme by Morokuma which was applied quantitatively to metal-ligand
>complex, the reference to which is Frey and Davidson, J. Chem. Phys. 90,
>5555, (1989).  This paper should also have the back references which
>would
>help you to theoretically understand Morokuma scheme.

---

From: Thomas Nowak <[email-masked]>
Date: Fri, 4 Feb 2000 21:39:46 +0100 (MET)

Dear CCLers,

We want to profile Gaussian98 on an SGI workstion running on IRIX 6.5 or
a HP X-Class workstaion running under HP-UX spp2000 B.10.01.
On the SGI the profiling switch is no longer supported, and whit speedshop 
I see only the g98 executibale, so I think I must use pixie on the
intresting executibales, but if I try I get an error messages:
Could not map rld from file rld.pixn32

On our HP we have compiled the whole program with the -p switch and set
the enviroment variable  PROFDIR=. , so that each executable should write
its own profile-file. Here G98 writes an core file very soon in g98 after
start. So I dont know whats go wrong on it!

Thanks

Thomas Nowak