Viral Capsid Assembly and Orientational Phase Transitions

The Landau theory of orientational phase transition has successfully been used to investigate liquid crystals, quasicrystals, metallic glasses and Fermi liquids. In this talk, we explore its connection to the assembly of icosahedral viruses. The theory predicts two kinds of ordering transition: (i) a robust first-order transition with states dominated by achiral even spherical harmonics (ii) a transition to icosahedral states formed by a mixture of even and odd spherical harmonics, where chirality plays an important role. In the latter case, the transition is either continuous or weakly first-order and the icosahedral state is in strong competition with tetrahedral, octahedral and five-fold symmetric states.