  Graph neural networks are widely used in machine learning applied to
chemistry, and in particular for material science discovery. For crystalline
materials, however, generating graph-based representation from geometrical
information for neural networks is not a trivial task. The periodicity of
crystalline needs efficient implementations to be processed in real-time under
a massively parallel environment. With the aim of training graph-based
generative models of new material discovery, we propose an efficient tool to
generate cutoff graphs and k-nearest-neighbours graphs of periodic structures
within GPU optimization. We provide pyMatGraph a Pytorch-compatible framework
to generate graphs in real-time during the training of neural network
architecture. Our tool can update a graph of a structure, making generative
models able to update the geometry and process the updated graph during the
forward propagation on the GPU side. Our code is publicly available at
https://github.com/aklipf/mat-graph.
