`"EII"`

spherical, equal volume

`"VII"`

spherical, unequal volume

`"EEI"`

diagonal, equal volume and shape

`"VEI"`

diagonal, varying volume, equal shape

`"EVI"`

diagonal, equal volume, varying shape

`"VVI"`

diagonal, varying volume and shape

`"EEE"`

ellipsoidal, equal volume, shape, and orientation

`"EVE"`

ellipsoidal, equal volume and orientation (*)

`"VEE"`

ellipsoidal, equal shape and orientation (*)

`"VVE"`

ellipsoidal, equal orientation (*)

`"EEV"`

ellipsoidal, equal volume and equal shape

`"VEV"`

ellipsoidal, equal shape

`"EVV"`

ellipsoidal, equal volume (*)

`"VVV"`

ellipsoidal, varying volume, shape, and orientation