Direct MD Simulations of Terahertz Absorption and 2D Spectroscopy Applied to Explosive Crystals.
A direct molecular dynamics simulation of the THz spectrum of a molecular crystal is presented. A time-dependent electric field is added to a molecular dynamics simulation of a crystal slab. The absorption spectrum is composed from the energy dissipated calculated from a series of applied pulses characterized by a carrier frequency. The spectrum of crystalline cyclotrimethylenetrinitramine (RDX) and triacetone triperoxide (TATP) were simulated with the ReaxFF force field. The proposed direct method avoids the linear response and harmonic approximations. A multidimensional extension of the spectroscopy is suggested and simulated based on the nonlinear response to a single polarized pulse of radiation in the perpendicular polarization direction.
†Fritz Haber Research Center for Molecular Dynamics, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Katz
‡Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, United States.
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Zybin
‡Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, United States.
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Goddard
¶Chemistry Department, NRCN, P.O. Box 9001, Beer-Sheva 84190, Israel.|§Bio-Medical Engineering, Ben-Gurion University, Beer-Sheva 84105, Israel.
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Zeiri
†Fritz Haber Research Center for Molecular Dynamics, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Kosloff
ReaxFF force field; THz spectroscopy; crystal slab; cyclotrimethylenetrinitramine; molecular dynamics; triacetone triperoxide