Hi,

I don't know if this is the right section, it might also fit into 'define'.

I would like to calculate certain perrhenates starting with the simple perrhenate anion ReO4-. To produces energies comparable to a certain publication, I would like to use 6-311G(d,p) for oxygen and a lanl2dz ECP for rhenium. As I had troubles defining the lanl2dz ECP in define, I used def2-TZVP/def2-ecp for Re, 6-311G-pol for O and ri.

The input struture has been optimized with a different QM code to be sure to have a good input. It is basically a tetrahedral geometry as expected. When I run a geometry optimization, the geometry gets planar and the bond lengths become very short. I also have to restart the calculation, as it stops due to convergence errors.

Can someone give me a hint?

Thanks,

Wilhelm