Simulation of two-dimensional infrared Raman spectroscopy with application to proteins

Two-dimensional infrared Raman spectroscopy is a powerful technique for studying the structure and interaction in molecular and biological systems. Here, we present a new implementation of the simulation of the two-dimensional infrared Raman signals. The implementation builds on the Numerical Integration of the Schr ̈odinger Equa- tion approach. It combines the prediction of dynamics from molecular dynamics with a map-based approach for obtaining Hamiltonian trajectories and response function calculations. The new implementation is tested on the amide-I region for two pro- teins, where one is dominated by α-helices and the other by β-sheets. We find that the predicted spectra agree well with experimental observations. The present imple- mentation and findings pave the way for future applications for the interpretation of two-dimensional infrared Raman spectra.