Multisurface multimode molecular dynamical simulation of naphthalene and anthracene radical cations by using nearly...

Area of Science:

• Quantum chemistry
• Computational physics
• Molecular dynamics

Background:

• Naphthalene and anthracene radical cations are crucial for understanding complex photoelectron spectra and nonradiative decay.
• Strong vibronic coupling in polynuclear hydrocarbons necessitates advanced computational methods.
• Existing methods may struggle with large-dimensional quantum systems.

Purpose of the Study:

• To demonstrate the efficiency of a parallelized time-dependent discrete variable representation (TDDVR) algorithm.
• To simulate the dynamics of naphthalene and anthracene radical cations.
• To validate the parallel TDDVR approach for large, vibronically coupled quantum systems.

Main Methods:

• Parallelization of the time-dependent discrete variable representation (TDDVR) algorithm using a shared-memory scheme.
• Theoretical simulation of naphthalene and anthracene radical cations.
• Comparison with the Multi Configuration Time-Dependent Hartree (MCTDH) method.

Main Results:

• The parallel TDDVR algorithm shows near-linear scalability with an increased number of processors.
• Simulations achieved significant speed-up, enabling calculations within reasonable timeframes.
• Theoretical photoelectron spectra accurately reproduced experimental features.
• Dynamical outcomes aligned well with established quantum dynamical methods like MCTDH.

Conclusions:

• The parallelized TDDVR method is efficient for simulating dynamics in large, multi-state, vibronically coupled systems.
• This approach provides accurate theoretical spectra and dynamical information for complex molecules.
• The developed code offers a viable and scalable alternative for advanced molecular dynamics simulations.