[DFTB-Plus-User] About dispersion

[hmanzano at labein.es]

Dear all,

>Unfortunately, up to now, the dispersion parameters had only be
>determined for O, N, C, H, P

If I  understood OK from the dftb+ manual, you need the polarizabilities 
of the atoms, the charge, and a covalent radius, and then the dispersion 
parameters are calculated from them acording to some formulas in the 
reference:

 M. Elstner, P. Hobza, T. Frauenheim, S. Suhai, and E. Kaxiras. Hydrogen
bonding and stacking interactions of nucleic acid base pairs: a
density-functional-theory based treatment. J. Chem. Phys., 114:5149,
2001. 20, 35, 36

So you can serch only the experimental or theoretical  atomic static 
polarizabilities for your atoms. Please correct me if I am in a mistake, I 
have started with dftb+ just few time ago. I attach two articles with 
static polarizabilities for the elements from Li to Ca.

>  This system contain chlorophyls, pheophytins and proteins consisted of 
C, N, O, H, S and Mg.

Are the Mg-X slako tables in the web-page? Is there any Mg-Si interaction?

Regards




____________________________
Hegoi Manzano Moro

e-mail:  hmanzano at labein.es 
Tel:   94 607 3300  ext. 2774
Fax: +34-946073349

Nanomaterials on construction , NANOC.
LABEIN-TECNALIA
C/ Geldo, edif 700
Parque Tecnológico de Bizkaia
48160 Derio, Bizkaia
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