Problems for Energy 1,4

From: Pascal Bonnet <>
Date: Tue 21 Dec 1999 16:45:22 -0800


I have a molecule with dummy atoms situated between carbons (on the middle of
the C-C bond). So, this dummy atoms are included in the main chain.
The problem is with the vdW interactions, the energy is very large. The reason
is quite simple:

C1-C2-C3-C4 The interaction between C1 and C4 is 1-4vdW (scaled by a 0.5
but in adding the dummy atoms we obtain:
Now, the interaction between C1 and C4 IS NOT CONSIDERED a 1-4 vdW (there are 6
bonds between them), so it is not scaled and the energy is very large and we've
got longer distances.

Is there any way to play a trick on the program in a way to obtain the same vdW
energy with and without dummies?

Thanks in advance..

Pascal Bonnet                       Tel: 34935811266 
Unitat Quimica Organica             Fax: 34935811265  
Facultat de Ciences                 Email
Universitat Autonoma de Barcelona
08193 Bellaterra (Barcelona)
Received on Tue Dec 21 1999 - 16:45:22 PST
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