Subject: Cl Parametres: Summary.

From: Mrigank <[email-masked]>
Date: Mon, 21 Aug 95 21:18:30 +0530

Some time back I posted a querry as follows:

I am doing some simulations which includes a molecule containing Chlorine. Can
any one suggest NB, angle and dihedral angle parametrs for it. For anlgels it
is attached to a benzene ring substituting hydrogen.  I would appreciate
parameters that will go with AMBER 91 or OPLS force field. 

These are the responses :
________________________________________________________________________
From: Garcia Edgardo <[email-masked]>

We are using the following vdW parameters in our
simulations:

Cl  Re= 3.513  E=0.227, They are from UFF 1.01 corrected for OPLS 
functional form.
__________________________________________________________________________
From: [email-masked]

You might want to look at the params we used for Br in nucleic
acids in

    Effects of Nucleotide Bromination on the Stabilities  of  Z-
    RNA and Z-DNA:
    A Molecular Mechanics / Thermodynamic Perturbation Study.
    W. S. Ross, C. C. Hardin, I. Tinoco, Jr., S. N. Rao,  D.  A.
    Pearlman and P. A. Kollman.
    Biopolymers 28, 1939 (1989).

for general comparative purposes.. the angle/bending/dihedral
params were chosen by analogy w/ other params, so no special
authority is implied.
_________________________________________________________________________
From: [email-masked] (Oyvind Edvardsen)

For the NB parameters of Cl I used (some years ago) 1.95 A for the vdW radius
and 0.2 kcal mol-1 for the well depth. The radius was extrapolated from the
radii of S and P, and the well depth was the same as for S and P. These 
parameters were suggested by prof. P. A. Kollman. 
Angle and torsion parameters used, were equal to the generalized X-CA-X and
X-CA-CA-X parameters in the AMBER 3.0 force field.

Veenstra et al, J. Comput. Chem. 1992, 13(8), 971-78, used 2.25 A and 0.2 for
CH3Cl NB params.
______________________________________________________________________________
From: Lipkowitz <[email-masked]>

A list of published force field parameters exists as Appendix I in Reviews in
Computational Chemistry, Volume 6, VCH Publishers, 1995. I don't recall if the
Cl parameters you need are in there, but, it's a good source of information
about parameters for various EFFs. Kenny
_______________________________________________________________________________

Thanks to all.
Mrigank
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