How Reliable Are Modern Density Functional Approximations to Simulate Vibrational Spectroscopies?

ABSTRACT: We show that properties of molecules with low-frequency modes calculated with density functional approximations (DFAs) suffer from spurious oscillations along the nuclear displacement coordinate due to numerical integration errors. Occasionally, the problem can be alleviated using extensive integration grids that compromise the favorable cost-accuracy ratio of DFAs. Since spurious oscillations are difficult to predict or identify, DFAs are exposed to severe performance errors in IR and Raman intensities and frequencies or vibrational contributions to any molecular property. Using Fourier spectral analysis and digital signal processing techniques, we identify and quantify the error due to these oscillations for 45 widely used DFAs. LC-BLYP and BH&H are revealed as the only functionals showi

SUBMITTER: Sitkiewicz SP 

PROVIDER: S-EPMC9251762 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature