Subject: Change basis set in G98

From: "Pablo Vitoria" <[email-masked]>
Date: Thu, 09 Nov 2000 11:33:28 +0100

Hi Huajun,

You can use guess=read with DFT and HF methods when changing basis set,
geometry of the molecule and even if you add some atoms to your molecule,
for example calculating a dimer after the monomer as long as you keep the
order of the atoms. (It works!)

In fact, I use this method very often in calculations involving transition
metal elements, which have convergence problems. I run a calculation with a
"small" basis set, faster and easier to converge, check if it converged to
the correct electronic state, and then I run a final calculation with a
bigger basis set using guess=read.

I am not an expert in G98 internals, but as far as I know, the program reads
the orbitals from the checkpoint file, and then proyects them to the new
basis set.

Best regards

Pablo

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Pablo Vitoria Garcia
Dpto. Quimica Inorganica, Facultad de Ciencias
Universidad del Pais Vasco (UPV/EHU)
Aptdo. 644
E-48080 Spain

Phone: +34 94 6015529/5522
Fax: +34 94 4648500
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