Rigid rotor wavefunctions are given by \( Y_{l,m}(\theta, \phi) \). The wavefunctions \( Y_{1,0}(\theta, \phi) \) and \( Y_{2,0}(\theta, \phi) \) are given below:
\[
Y_{1,0}(\theta, \phi) = \sqrt{\frac{3}{4\pi}} \cos \theta \qquad
Y_{2,0}(\theta, \phi) = \sqrt{\frac{5}{16\pi}} (3\cos^2 \theta - 1)
\]
For a non-polar diatomic molecule, the value of transition dipole moment integral for the transition between \( Y_{1,0}(\theta, \phi) \) and \( Y_{2,0}(\theta, \phi) \) is equal to: