  Ion parallel closures are obtained for arbitrary atomic weights and charge
numbers. For arbitrary collisionality, the heat flow and viscosity are
expressed as kernel-weighted integrals of the temperature and flow-velocity
gradients. Simple, fitted kernel functions are obtained from the 1600 parallel
moment solution and the asymptotic behavior in the collisionless limit. The
fitted kernel parameters are tabulated for various temperature ratios of ions
to electrons. The closures can be used conveniently without solving the kinetic
equation or higher order moment equations in closing ion fluid equations.
