The specific heat C-p is correlated to the frequency shifts (1/v)(partial derivative v/partial derivative T)(p) in ammonia solid I close to the melting point. Our calculated Raman frequencies for the translational modes of v(T) (100 cm(-1)) and v(T) (130 cm(-1)), are used for this correlation for the pressures of 0, 1.93 and 3.07 kbar in this crystalline system. We obtain that the specific heat varied linearly with the frequency shifts for those pressures studied and values of the slope dP(m)/dT were extracted. The observed behaviour of the ammonia solid I near the melting point is explained on the basis of our spectroscopic modification of the first Pippard relation. (C) 2006 Elsevier B.V. All rights reserved.