Gradient-based Methods for Determination of Cluster Structures at Zero Temperature

1 Gradient-based Methods for Determination of Cluster Structures at Zero Temperature 

Notice that in spite of considerable progress in developing gradient-based methods the identification of the stable isomers and particularly precise determination of their energy sequence on the flat energy surfaces of metal cluster is still a difficult task. 

In the framework of our earlier studies we usually started from the HF optimized isomeric forms and recalculated their energy sequence at the large-scale configuration interaction (Cl) level at which the excited states have also been determined. In the case where correlation effects strongly influenced the energy sequence of isomers we also carried out geometry optimization at the correlated level of theory either using GDF or CCSD techniques. 

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