Use moCoefficients for read and write
Use moCoefficients for read and write

Still need to sort out the alpha/beta logic, but ensure round trip of
GTOs work as expected.

Signed-off-by: Marcus D. Hanwell <cf7042e2e8eee958b5bcde1ae2cbefef82efc184@kitware.com>

ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs