The dimensionless species- neoclassical viscosity matrix,
(see Section 2.17), is defined to have the following elements [7]:
(Note that the viscosity matrix elements defined here differ from those defined in Section 2.17 by a factor .)
Here,
and
Furthermore,
and, finally,
Note that our expressions for the neoclassical viscosity matrices interpolate in the most accurate manner possible
between the three standard neoclassical collsionality regimes (i.e., the banana, plateau, and Pfirsch-Schlüter regimes [8]) [7].