and ammonia decomposition conditions . Additionally, by staying above 135 °C, liquid ammonia will not occur . The "small" data set covers a smaller pressure range of 1 -100 bar, whereas the temperature range of 135 -1000 °C is the same. On both data sets, uniform and log-uniform sampling strategies are applied, yielding a total of four training data sets as summarized in Table . The amount of training data per set was set to 𝑁 = 10 6 samples, which has proven to be sufficient in preliminary experiments. In other words, further increasing the amount of training data did not lead to different results. Each data set is divided into training, validation and test data sets with a ratio of 7/1/2.