This notebook explores the rotational dynamics of a triatomic molecule by numerically solving Euler’s equations for the free rotor to obtain the angular velocity in the body fixed frame,ω(t). Euler matrices R(Θ) are employed to express ω(t) in terms of the Euler angles and its time derivatives, Θ and
. The solution of the first order differential equation
(ω(t),Θ) gives the Euler angles as functions of time Θ(t). Finally, the rotation of the molecule and its fixed coordinate frame, with respect to the space fixed frame, is obtained by applying the time dependent Euler rotation R(Θ(t)) to the position vector of the atoms of the molecule.