Mackay has made important scientific contributions related to the structure of materials: In 1962 he published a manuscript that showed how to pack atoms in an icosahedral fashion; a first step towards five-fold symmetry in materials science.[2] These arrangements are now called Mackay icosahedra. He is a pioneer in the introduction of five-fold symmetry in materials and in 1981 predicted quasicrystals in a paper (in Russian) entitled "De Nive Quinquangula"[3] in which he used a Penrose tiling in two and three dimensions to predict a new kind of ordered structures not allowed by traditional crystallography. In a later manuscript, in 1982, he took the optical Fourier transform of a 2-D Penrose tiling decorated with atoms, obtaining a pattern with sharp spots and five-fold symmetry.[4] This brought the possibility of identifying quasiperiodic order in a material through diffraction. Quasicrystals with icosahedral symmetry were found by Dan Shechtman and co-workers in 1984.[5]
Mackay has been interested in a generalised crystallography, which can describe not only crystals, but more complex structures and nanomaterials.[7][8] He has applied his ideas of minimal surfaces to graphitic materials, proposing, with Humberto Terrones, periodic arrangements of carbon atoms with negative Gaussian curvature known as Schwarzites, which are the periodic cousins of Buckminsterfullerenes[9][10]
Mackay has compiled a book of scientific quotations[11] and has co-authored a book on geometry with Eric Lord and S. Ranganathan.[12] He has also written a book of poetry[13] and has translated from the German, with commentaries, Ernst Haeckel's last book "Kristallseelen", (1917).[14] He produces scientifically inspired visual art under his artistic pseudonym Sho Takahashi. Some of his 3D printed minimal surface designs can be found at his shapeways store.[15]
^Alan L. Mackay, "A dense non-crystallographic packing of equal spheres", Acta Crystallogr. Vol. 15, 916 (1962).
^Alan L. Mackay, "De Nive Quinquangula", Krystallografiya, Vol. 26, 910–9 (1981).
^Alan L. Mackay, "Crystallography and the Penrose Pattern", Physica 114 A, 609 (1982).
^D. Shechtman, I. Blech, D. Gratias, and J. Cahn, "Metallic Phase with Long-Range Orientational Order and No Translational Symmetry". Physical Review Letters 53: 1951 (1984).
^Alan L. Mackay, Comp. & Maths. with Appls. "Generalised Crystallography", Vol. 12B, No 1-2, 21 (1986).
^Julyan H. E. Cartwright and Alan L. Mackay, "Beyond crystals: the dialectic of materials and information", Phil. Trans. Roy. Soc. A, 28 June 2012 vol. 370 no. 1969, 2807–2822.
^Alan L. Mackay, & Humberto Terrones, "Diamond from Graphite", Nature, Vol. 352, 762 (1991).
^Humberto Terrones & Alan L. Mackay, "The geometry of Hypothetical Curved Graphite Structures", Carbon, Vol. 30, No. 8, 1251 (1992).
^Alan L. Mackay, "A dictionary of scientific quotations", Taylor & Francis, ISBN978-0750301060 (1991).
^Eric A. Lord, Alan L. Mackay, & S. Ranganathan, "New geometries for new materials", Cambridge University Press, ISBN978-0521861045 (2006).
^Alan L. Mackay, "The floating world of science", Lulu.com (2011).
^Alan L. Mackay, "Ernst Haeckel and Biological Form", Lulu.com (2007).