For example, the molar heat capacity of nitrogen N 2 at constant volume is 20.6 J⋅K ⋅mol (at 15 °C, 1 atm), which is 2.49 R. From the theoretical equation c V,m = ⁠ 1 / 2 ⁠ fR, one concludes that each molecule has f = 5 degrees of freedom. These turn out to be three degrees of the molecule's velocity vector, plus two degrees from its rotation about an axis through the center of mass and perpendicular to the line of the two atoms. The degrees of freedom due to translations and rotations are called the rigid degrees of freedom, since they do not involve any deformation of the molecule.