1. We have the following Poisson brackets.
2. where ps are momentum. If qs=c1x1+c2x2+…cnxn are normal coordinates of the system, we have.
3. Making use of Eqs. (3), (4) and (5), we have.
4. We can obtainls from Eq. (6), then cs and qs can be obtained. Lie algebraic structure and the Poisson conservation law Under the normal modes, the equations of motion are.
5. We discuss the algebraic structures of normal modes, introducing 2n contravariant vectors.