The **RNA7A** model is the most general of the seven state models. It
has 21 rate parameters (including the reference rate
**AU**
**GC**) and 7 frequencies. All mismatches
are treated in a single state MM.
The **RNA7A** model is described by the following rate matrix
(table 2.8).

Gowri-Shankar Vivek 2003-04-24