If the virus actually manifested the capsomer orientations dictated by Caspar-Klug theory, its constituent proteins would be out of whack by angles of 30 degrees or more from where they've been observed, Twarock and Roger W.
Virologists refer to these panels as pentamers and hexamers or, collectively, capsomers.
They developed a computer model that treated capsomers as malleable disks.
In each configuration, the faux capsomers would push and tug on each other with forces whose values the researchers assigned, in part, according to measurements of real viruses.
For successive numbers of disks from 12 to 72, the researchers started with the capsomers scattered across a spacious sphere and slowly shrank it until the capsomers became crowded together.
The lowest-energy configurations emerged during the modeling runs with 12, 32, 42 and 72 capsomers.
A virologist colleague had shown Twarock a 1991 scientific article that reported that every one of the 72 capsomers of a polyoma-type virus called Simian Virus 40 (SV-40) is a pentamer.