Spherical capsid phase diagram.

We describe two specific capsid sizes that remain to be elucidated ( and ; the diagram arbitrarily assumes that ). describes the limit of the geometric domain, beyond which our geometric assumptions and predictions may not hold. We expect that all capsid sizes greater than will be exclusively described by continuum elasticity. We also expect that, beyond (i.e., in the purely continuum domain), the Föppl-von Karman number () [27], [28] that dictates spherical vs. icosahedral morphology will depend primarily on , and so there will be a capsid size () that demarcates the allowance for spherical and icosahedral morphologies in the purely continuum regime (the sigmoidal curve represents the dependence of and hence morphology on ). These assumptions consolidate all observed instances of spherical capsid morphology.