From the perspective of spontaneity , the interplay between -TS and H determines the direction of a reaction. For processes with a positive entropy change (ΔS>0), the -TS term reduces ΔG, favoring spontaneity even in endothermic reactions (H>0), especially at elevated temperatures. Conversely, when entropy decreases (ΔS<0), the positive contribution of -TS increases ΔG, opposing spontaneity unless compensated by a sufficiently negative enthalpy (H<0). These observations align with thermodynamic principles and underscore the critical role of the temperature-dependent entropy term in influencing free energy and driving spontaneous changes. The DMol3 calculation findings thus reinforce the theoretical framework of the Gibbs free energy equation in predicting reaction spontaneity.