Wavelet transform analysis of ab initio molecular dynamics simulation:: Application to core-excitation dynamics of BF3

We propose a novel analysis method of ab initio molecular dynamics (AlMD) simulation using a confinuous wavelet transform (c-WT) technique. The c-WT technique, one of the time-frequency signal analysis methods, provides a clear view of the dynamical information in time developments. Combined with the auto-correlation function of velocity by AIMD simulation, c-WT analysis enables us to well understand dynamical distribution, such as the vibrational properties following a change of electronic structure in a molecular system. As a practical application, AIMD simulation of core-excited BF3 (Bls -> 2a(2)(")) is illustrated. AIMD simulation leads to the change of vibrational motion as well as structural deformation by core-excitation. The c-WT analysis clarifies the relationship between structural deformation and the related significant vibrational modes in core-excitation within 50 fs. (C) 2007 Wiley Periodicals, Inc.