The carboxylate methoxy clusters of the ‘wheels’ type: [Crn(OCH3)2n ((CH3)3COO)n] (n = 4,6,8,10,12) were investigated with the aim to find the most stable of the compounds. Calculations on their geometrical and electronic characteristics have been performed for the definition of the total energy (Etot per one Crcontaining co-ordination section of the compounds). All these complexes were studied in their ground ferromagnetic state. Their geometries were obtained on the basis of the MM2/MM3 method from the HyperChem’s computational package and found very close to the known X-ray data*. Their electronic structure was calculated by means of the Hartree-Fock and DFT (B3LYP functional) methods, using the basis set STO-3G from GAUSSIAN 2003 package. Main results are in Figs. 1,2.Fig.2 The most stable structure (n=10) The calculated by both of the above mentioned methods results have led us to the conclusion, that the macrocycle with n=10 (see Figs.1,2) is the most stable one from all systems investigated. Acknowledgment. This work was supported by INTAS(No.03-51-4532). *McInnes E., Anson Ch., Powell A., Thomson A., Sessoli R. Chem. Comm., 2001, 89-90.