Universal correlations of T-c ion mass scaling with distance

We present a short overview of the critical temperature correlations with d ifferent parameters for low and high T-c superconductors. The overview unde rlines the importance of crystalline structure in determining the critical temperature value. The structure of copper-based superconductors is studied in comparison with low-temperature superconductors and a new correlation o f the transition temperature is found, Namely, the layered structure, more exactly a certain distribution of the mass of the ions along the e-axis is the key factor in determining the "intrinsic" critical temperature, paramet er introduced by Kresin et al. [4].