title: Investigating anharmonicity using molecular dynamics calculations: the TM hydride series (PH(3))(3)MH(4), (M = Os, Ru and Fe).
abstract: We present an ab initio molecular dynamics study of the iron triad complex (PH(3))(3)MH(4), (M = Os, Ru and Fe). We calculate numerical atomic probability density functions (PDFs), which offer direct visualisation of the degree of anharmonicity present in these complexes. Fitting our calculated PDFs to a parabolic transformation of the standard crystallographic ellipsoidal PDF allowed the bond correction for librational motion observed in the M-H distances to be obtained. For the Ru and Fe complexes we also attempt to quantify the bond distance correction needed to describe the eta(2)-bound H(2) ligand anharmonically. From our simulations we also obtain anharmonic vibrational spectra, which we compare to experimental data. Finally, we also comment on a spontaneous H(2)/(H)(2) ligand flipping process observed for the Fe complex.
authors.affiliation: School of Chemistry and EaSTCHEM Research School, The University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, UKEH9 3JJ.
authors.forename: Carole A
authors.initials: CA
authors.lastname: Morrison
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Reilly