Convert from crith to packen [Russia]

Unit Definition (crith)
The crith is a unit of mass sometimes used in the physics and chemistry of gases. The crith is equal to the mass of a liter of hydrogen at standard temperature (0.01°C) and pressure (1 atmosphere); this is about 89.885 milligrams. The name comes from an ancient Greek word for a barleycorn.

Unit Definition (packen [Russia])
The packen is a traditional Russian unit of weight equal to 1200 funte, 30 pudi, 1083 pounds, or 491.4 kilograms.