How Reliable Are Modern Density Functional Approximations to Simulate Vibrational Spectroscopies?
Sebastian P SitkiewiczRobert ZaleśnyEloy Ramos-CordobaJosep M LuisEduard MatitoPublished in: The journal of physical chemistry letters (2022)
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 showing robustness against the spurious oscillations of various energy, dipole moment, and polarizability derivatives with respect to a nuclear displacement coordinate. Given the ubiquitous nature of molecules with low-frequency modes, we warrant caution in using modern DFAs to simulate vibrational spectroscopies.
Keyphrases
- working memory
- density functional theory
- molecular dynamics simulations
- energy transfer
- raman spectroscopy
- patient safety
- adverse drug
- emergency department
- optical coherence tomography
- early onset
- mass spectrometry
- magnetic resonance imaging
- molecular dynamics
- single cell
- simultaneous determination
- magnetic resonance
- drug induced
- electronic health record
- liquid chromatography
- quantum dots
- gas chromatography