Finite-temperature characterization of ferrocene from first-principles molecular dynamics simulations

Abstract
A first‐principles molecular dynamics calculation of ferrocene [Fe(C5H5)2] at 300 K, based on the local density approximation, is presented. Kohn–Sham equations and forces on the atoms are obtained using the projector augmented wave technique. Frequencies and eigenmodes are derived by fitting a system of harmonic oscillators to the molecular dynamics trajectory. Frequency shifts for deuterated ferrocene [Fe(C5D5)2, ferrocene‐d 10] and the corresponding eigenvectors are obtained by diagonalizing the dynamical matrix after renormalizing it according to the changed masses. Most experimental and theoretical frequencies agree to about 2.5% (or 20 wave numbers), with the exception of six modes for which a new assignment is proposed.