What is R in the Debye Heat Capacity Equation?

[axawire]

I am currently re-reading an old textbook on thermal physics and they have listed the final result for calculating the Debye Heat Capacity as

C =9R(T/ThetaD)^3*Integral((z^4*e^z dz)/(e^z-1)^2, 0-->ThetaD/T)

But they fail to mention what the R in this equation is, Could some one please tell me what R is?

Thanks.

 

[lightarrow]

I am currently re-reading an old textbook on thermal physics and they have listed the final result for calculating the Debye Heat Capacity as

C =9R(T/ThetaD)^3*Integral((z^4*e^z dz)/(e^z-1)^2, 0-->ThetaD/T)

But they fail to mention what the R in this equation is, Could some one please tell me what R is?

Thanks.

Gas constant. The one in PV = nRT
R = 8.314 Joule/mol°K