The diffusion process comprises a forward process, which the stochastic degradation (or corruption) of the crystal structures, while the reverse process iteratively learns the pattern to gradually reconstruct the data distribution from pure noise. The forward process is 𝑞(𝐶 where 𝐶𝑎𝑡(𝑥; 𝑝) represents a categorical probability distribution with parameter 𝑝 , and 𝑄 k , = 𝑄 : 𝑄 G … 𝑄 , is the cumulative product of the transition matrices 𝑄 , at each time step. 𝑇, The absorbing transition matrices in the D3PM approach is adopted, where it is designed to transform 𝐴 C into dummy atom, of which atomic number is zero, at the final time step.