Extension of SGTE data for pure elements to zero Kelvin temperature—A case study

A method for the extension of SGTE Gibbs energy expression for pure elements to zero Kelvin temperature is described. The method is based on the Einstein formula for the temperature dependence of heat capacity extended to give the temperature dependence of the Gibbs energy below the limiting temperature of validity of SGTE unary data (Tlim). The method maintains the SGTE unary data above the limiting temperature and forces the low temperature extension to have the same function value and the value of the first derivative at Tlim as the respective SGTE Gibbs energy polynomial. The extended heat capacity polynomials were also set to have the same function value and the value of the first derivative at Tlim.

► The method extends the SGTE Gibbs energy expression of pure elements to zero Kelvin. ► Extended expression of Gibbs energy is based on the Einstein formula for heat capacity. ► SGTE Gibbs energy and heat capacity are smoothly joined to their extension.