Computational infrared and Raman spectra by hybrid QM/MM techniques: a study on molecular and catalytic material systems

Vibrational spectroscopy is one of the most well-established and important techniques for characterizing chemical systems. To aid the interpretation of experimental infrared and Raman spectra, we report on recent theoretical developments in the ChemShell computational chemistry environment for modelling vibrational signatures. The hybrid quantum mechanical and molecular mechanical approach is employed, using density functional theory for the electronic structure calculations and classical forcefields for the environment. Computational vibrational intensities at chemical active sites are reported using electrostatic and fully polarizable embedding environments to achieve more realistic vibrational signatures for materials and molecular systems, including solvated molecules, proteins, zeolites and metal oxide surfaces, providing useful insight into the effect of the chemical environment on the signatures obtained from experiment. This work has been enabled by the efficient task-farming parallelism implemented in ChemShell for high-performance computing platforms. This article is part of a discussion meeting issue 'Supercomputing simulations of advanced materials'.

Automated summary

Vibrational spectroscopy is crucial for characterizing chemical systems, and recent theoretical developments in the ChemShell computational chemistry environment are reported to aid the interpretation of experimental infrared and Raman spectra. Computational vibrational intensities were calculated using a hybrid quantum mechanical and molecular mechanical approach, providing more realistic vibrational signatures for various materials and molecular systems. The efficient task-farming parallelism implemented in ChemShell on high-performance computing platforms enabled this work. This article is part of a discussion meeting issue on supercomputing simulations of advanced materials.