Dear all:

I am trying a simple check for the ADF results on a square-planar (CuCl4)2-
complex. I am using basis IV and VWN functional. The calculated equilibrium
geometry corresponds to a Cu-Cl distance of about 2.27 Angs, that compares
very well with the experimental data. However, the electronic structure is
not very good when it is compared to the experimental data. So, the p(Cl)
levels are too close (by about 1 eV) to the d(Cu) ones and the charge
distribution of the unpaired electron is mainly located on the Cl against
the experimental evidence.

I have made different calculations changing the basis quality, functional,
inserting the complex in different lattices,... and the results are
similar. I have found the same problem in other D4h complexes of Cu2+ and
Ag2+ ions (d9 configuration), like (CuCl6)4- or (AgF6)4-.

I know that other people have found this kind of problems. Does anybody
know about the origin of this problem? Is it due to the ADF basis sets for
this ions?

Best regards.

Antonio Aramburu

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Antonio Aramburu-Zabala
Departamento de Ciencias de la Tierra y Fisica de la Materia Condensada
Facultad de Ciencias
Universidad de Cantabria
Avenida de los Castros s/n
39005 Santander (Spain)

Phone: 34 - 942 201507
Fax: 34 - 942 201402
e-mail: aramburu_at_materiales.unican.es
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Received on 2001-11-22 12:55:50