Determining the effects of clumping and porosity on the chemistry in a non-uniform AGB outflow M. Van de Sande, J. O. Sundqvist, T. J. Millar, D. Keller, W. Homan, A. de Koter, L. Decin and F. De Ceuster A&A, 616 (2018) A106 Published online: 28 August 2018 DOI: 10.1051/0004-6361/201732276