Parameterisation of Arsenic

[Aaron]

> Does anyone know how to parameterise an arsenic atom within X-plor? 
> Please e-mail me on j.k.hogg at bris.ac.uk

You will need the SCATter parameters, which can be found
in the international tables for crystallography Vol. IV (Coefficients for
Analytical Approximation to the scattering factors)

SCATter ( chemical As)
    16.6723 2.63450 6.07010 0.264700 3.4310 12.9479 4.27790 47.7972 2.53100

This should go with the other SCATter terms in your prepstage, slowcool
etc files.

You will also need the V.D.W radii which are :

 !                  eps     sigma       eps(1:4) sigma(1:4)
 !                  (kcal/mol) (A)
 !                  ---------------------------------------

 NONBonded  AS         .0600 3.564       .0600 3.564

Which should be in a parameter file read with the parameter statement.

Hope this helps,

Aaron