Molecular dynamics simulation of a Lennard-Jones triatomic - time autocorrelation functions

Abstract

The reorientational dynamics of an asymmetric top (a C_2v symmetry triatomic) are investigated using molecular dynamics simulation. The angular momentum autocorrelation function <$\text{J}$(t).$\text{J}$(0)>/<J²(0)> is non-exponential with a very long positive tail. The autocorrelation functions <ℓ_A(t).$\text{ol}$_A(0)>, <$\text{ol}$_B(t).$\text{ol}$_B(0)> and <$\text{ol}$_C(t).$\text{ol}$_C(0)> of three unit vectors $\text{ol}$_A, $\text{ol}$_B and $\text{ol}$_C fixed in the principle moment of inertia coordinate system are non-exponential for each of the first four Legendre polynomials P₁ to P₄.