title: Fragment Molecular Orbital Nonadiabatic Molecular Dynamics for Condensed Phase Systems.
abstract: A method for efficiently simulating nonadiabatic molecular dynamics (NAMD) of nanoscale and condensed phase systems is developed and tested. The electronic structure, including force and nonadiabatic coupling, are obtained with the fragment molecular orbital (FMO) approximation, which provides significant computational savings by splitting the system into fragments and computing electronic properties of each fragment subject to the external field due to other all other fragments. The efficiency of the developed technique is demonstrated by studying the effect of explicit solvent molecules on excited state relaxation in the Fe(CO)4 complex. The relaxation in the gas phase occurs on a 50 fs time scale, which is in excellent agreement with previously recorded femtosecond pump-probe spectroscopy. Adding a solvation shell of ethanol molecules to the simulation results in an increase in the excited state lifetime to 100 fs, in agreement with recent femtosecond X-ray spectroscopy measurements.
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90037, United States.
authors.forename: Ben
authors.initials: B
authors.lastname: Nebgen
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90037, United States.
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Prezhdo