Sensitivity of microwave spectra of deuterated ammonia to variation of
  electron-to-proton mass ratio
  We estimate sensitivity coefficients Q_\mu to variation of the
electron-to-proton mass ratio \mu for microwave transitions in partly
deuterated ammonia NH2D and ND2H. Because of the mixing between rotational and
inversion degrees of freedom the coefficients Q_\mu strongly depend on the
quantum numbers of the transition. This can be used for astrophysical search
for possible variation of the constant \mu.
