eigenvalue = -8	mult 1
eigenvalue = -3.74166	mult 12
eigenvalue = -3.41421	mult 6
eigenvalue = -2	mult 8
eigenvalue = -0.585786	mult 6
eigenvalue = 0	mult 18
eigenvalue = 0.585786	mult 6
eigenvalue = 2	mult 8
eigenvalue = 3.41421	mult 6
eigenvalue = 3.74166	mult 12
eigenvalue = 8	mult 1