X * . The first three forms have been adopted frequently by previous studies , with the linear form being used most frequently . For the polynomial form, we chose a 3 rd -order polynomial based on the balance between accuracy and overfitting, which was observed by extraneous curvatures when the 4 th -order polynomial was used. We also employed an interpolative model that computes a value at a coverage of interest by linearly interpolating between two adjacent data points, one at coverage directly lower than and another at coverage directly greater than the coverage of interest. To the best of our knowledge, the interpolative model is employed for the first time. Because the heat capacity depends on temperature and coverage, we employed a log-quadratic expression (Equation ). Coefficients c 1 -c 8 were fitted from the DFT-derived thermodynamic parameters.