Impact of model architectures. For forward reaction prediction and retrosynthesis tasks, CodeT5 consistently outperformed Mistral and GPT2. Its encoder-decoder architecture likely contributes to this by constructing a structured latent representation of the input, enabling better transformation into the output space . In contrast, the decoder-only architectures of GPT2 and Mistral, designed for autoregressive generation, may be less suited for these structured prediction tasks.