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

Round 1

Reviewer 1 Report

   As part of their strategy to computationally characterize the microwave spectra of biomolecules, the authors describe here a subset of this strategy designed to provide highly accurate geometries of low-lying conformers. After explaining how their approach works in the general case of small molecules, they go on to test it out on some small amino acids.  The computational method involves high level theory, complete with large basis sets, but the authors explain how certain short cuts can provide comparably accurate data at acceptable computational cost.  The treatments go beyond the usual approximations, such as harmonicity, or limited basis set size, so are a complete means of considering this problem.  The explanations are clear and the conclusions compelling.  This manuscript offers a blueprint for attacking this complicated problem, so its publication is recommended as an advance in the analysis of spectra.

Reviewer 2 Report

In this work, Barone et al. employed a computational approach to provide rotational spectroscopy parameters for biomolecule building blocks. The high-resolution rotational spectroscopy plays an invaluable role in the investigation of biomolecule, so the work fits the current trends in chemistry well. The work presents very interesting research results. It is also well written. The calculations have been done carefully and no obvious errors or omissions could be detected by referee. Therefore, I can recommend publication this article in Molecules as it is.