  Using first-principles electronic structure calculations based on the Nth
order muffin tin orbital (NMTO)-downfolding technique, we derived the
low-energy spin model for CuTe2O5. Our study reveals that this compound is a 2D
coupled spin-dimer system with the strongest Cu-Cu interaction mediated by two
O-Te-O bridges. We checked the goodness of our model by computing the magnetic
susceptibility with the Quantum Monte Carlo technique and by comparing it with
available experimental data. We also present magnetization and specific heat
results which may be compared with future experimental investigations. Our
derived model is in disagreement with a recently proposed model for this
compound [J. Deisenhofer et al, Phys. Rev. B,74 (2006) 174421]. The situation
needs to be settled in terms of further experimental investigations.
