Toward Accurate yet Effective Computations of Rotational Spectroscopy Parameters for Biomolecule Building Blocks

The interplay of high-resolution rotational spectroscopy and quantum-chemical computations plays an invaluable role in the investigation of biomolecule building blocks in the gas phase. However, quantum-chemical methods suffer from unfavorable scaling with the dimension of the system under consideration. While a complete characterization of flexible systems requires an elaborate multi-step strategy, in this work, we demonstrate that the accuracy obtained by quantum-chemical composite approaches in the prediction of rotational spectroscopy parameters can be approached by a model based on density functional theory. Glycine and serine are employed to demonstrate that, despite its limited cost, such a model is able to predict rotational constants with an accuracy of 0.3% or better, thus paving the way toward the accurate characterization of larger flexible building blocks of biomolecules.

Automated summary

The interplay between high-resolution rotational spectroscopy and quantum-chemical computations is crucial for investigating biomolecule building blocks in the gas phase. However, quantum-chemical methods have scalability issues. In this study, a model based on density functional theory is proposed and demonstrated to accurately predict rotational constants for glycine and serine, providing a cost-effective approach for characterizing flexible building blocks of biomolecules.