Práce se zabývá srovnáním vysoce přesných kvantově mechanických výpočtů interakčních energií třinácti různých konformací systému 1-methyluracil dimeru, jakožto reprezentativního systému párů basí nukleových kyselin. Termodynamická analýza charakterizuje vzájemnou souhru enthalpie a entropie na vytváření preferovaných konformací systému.Theoretical analysis of the formation of 1-methyluracil dimer was performed. Stabilization energies of 13 different conformations were evaluated at a very high ab initio level by complete basis set limit calculations. In this work we compare accurate interaction energies estimated at CCSD(T)/CBS level with Density functional theory calculations DFT-D/BLYP/TZVP, DFTD/tpss/LP and with calculations of semiempirical methods SCC-DFTB and PM6-DH. All interaction energies were corrected for basis set superposition error (BSSE) with use of counterpoise correction. The thermodynamic characteristics were calculated using rigid rotor-harmonic oscillator-ideal gas approximations. Interaction enthalpie at 0 K were observed by including the zero point energies. Gibbs energies at various temperatures were calculated to include entropy influence. The present calculations allow us to make more general conclusions concerning the interplay of enthalpy and entropy in stabilizing DNA base pairs in vacuo.