3D chemical structure of diffuse turbulent ISM - I. Statistics of the HI-to-H2 transition E. Bellomi, B. Godard, P. Hennebelle, V. Valdivia, G. Pineau des Forêts, P. Lesaffre and M. Pérault A&A, 643 (2020) A36 Published online: 28 October 2020 DOI: 10.1051/0004-6361/202038593