First-principles computations coupled with simulated Xrd are used to investigate Li2CoSiO4 polymorphism with symmetries Pmn2(1), Pbn2(1) and P2(1)/n. We find that complex polymorphic structures can be characterized by transition metal ordering, which presents a fingerprint in the Xrd spectra. Li/Co mixing order is determined for beta(II)-Pmn2(1) polymorph, which provides a structural template to achieve highly stable intercalation cycling. We illustrate that the material properties of Li2CoSiO4 polymorphs depend on cationic orderings, and we offer insights on materials preparation under high pressure and heat. This may help realize new silicate materials using the strategy of solid solutions. (C) 2013 Elsevier B.V. All rights reserved.