Themed collection Challenges in spectroscopy: accuracy vs interpretation from isolated molecules to condensed phases

This themed issue includes a collection of articles on Challenges in spectroscopy: accuracy versus interpretation from isolated molecules to condensed phases.

The subject of this Perspective is quantum approaches, beyond the harmonic approximation, to vibrational dynamics and IR spectroscopy.

Core level binding energies, measured by X-ray photoelectron spectroscopy providing unique information regarding the chemical environment of atoms in a system, can be estimated by a diversity of state-of-the-art accurate methods here detailed.

We conducted MD simulations to provide a comprehensive study on the human aldehyde oxidase and on the impact that the allosteric inhibitor thioridazine and malonate ions have on its structure, particularly on the catalytic tunnel.

N₂⁺ + Rb → (N₂Rb)⁺(v) + ħω radiative association: partial vibronic cross-sections corresponding to the R₈ transition as a function of the emitted photon energies and wavelengths in the ultraviolet region.

Conformational changes of the monomeric safrole isolated in low temperature xenon matrices, induced thermally or using narrow-band UV radiation, represent challenging example for the theoretical structural, spectroscopic and energetic analysis.

Several significant improvements are proposed to the computational molecular spectroscopy protocol MARVEL (Measured Active Rotational–Vibrational Energy Levels), facilitating the inversion of a large set of measured rovibrational transitions to energy levels.

Two C–H⋯Cl–C and one C–H⋯F–C bonds stabilize (by 5.9 kJ mol⁻¹) the dimer of chlorofluoromethane observed by rotational spectroscopy in the gas phase. The spectral analysis is complicated by the quadrupolar effects of the two nonequivalent Cl nuclei.

The effective fragment potential (EFP) method for the efficient inclusion of solvation effects is combined with the algebraic diagrammatic construction (ADC) scheme for the second- and third-order polarisation propagator.

The rotational spectrum of monodeutero-oxirane was analysed as measured using the Zurich Gigahertz (GHz) spectrometer and our highest resolution Fourier Transform Infrared (FTIR) spectrometer system coupled to synchrotron radiation at the Swiss Light Source (SLS).

Rotational–vibrational states up to 3200 cm⁻¹, beyond the highest-lying stretching fundamental, are computed variationally for the vinyl radical (VR), H₂C_βC_αH, and the following deuterated isotopologues of VR: CH₂CD, CHDCH, and CD₂CD.

Two for a tango: the rotational spectrum of a cyclohexanol–water dimer evidences a concerted motion of the water molecule and the hydroxyl group of the ring.

An efficient approach is reported to estimate the rotational diffusion tensor of molecules from the global angular momentum autocorrelation functions obtained from short molecular dynamics trajectories.

Structure of the HKrCCH⋯CO₂ complex prepared in a low-temperature krypton matrix.

We present a theoretical-experimental study of the optical rotation of (R)-glycidylmethylether using a mixed quantum-classical model for solvent effects.

DNA intercalation and groove binding of two photoswitching dithienylethene derivatives have been studied and characterized by means of molecular dynamics and electronic circular dichroism.

UV and IR spectroscopic study of the controlled complexation and microhydration of a polycyclic aromatic hydrocarbon under isolated conditions using free electron laser FELIX.

We study the photodissociation of the potassium atom from a superfluid helium nanodroplet upon 5s ²S or 4p ²P excitation using the time-dependent helium density functional method (He-TDDFT). The results show possible K spin–orbit relaxation.

We adopted excited state ab initio dynamics and a new time resolved vibrational analysis to unveil coupling between modes promoting photorelaxation.

The equilibrium structure for 1-chloro-1-fluoroethene is obtained by high-level quantum chemical calculations and the semi-experimental approach.

The far infrared region of three detectable molecules sharing the empirical formula C₃H₃O₂N, acetyl isocyanate CH₃CONCO (AISO), methyl cyanoformate NC–COOCH₃ (MCN) and acetyl cyanate CH₃COOCN (ACN), is explored using explicitly correlated coupled cluster ab initio methods and a variational procedure designed for non-rigid species and large amplitude motions.

Crucial insight into lactic acid self-aggregation in solution is obtained by following its unique VCD spectral features in cold matrices.

First observation of the THz spectrum of ¹⁵ND. Global analysis of the imidogen radical spectra and derivation of the Born–Oppenheimer equilibrium bond length.

TDDFT simulations of the absorption and CD spectra of a Pd₂Au₃₆(SC₂H₄Ph)₂₄ monolayer-protected cluster (MPC) are carried out with the aim of investigating the effects of doping, conformational degrees of freedom of the thiolates’ end-groups, and charge states on its chiro-optical response.

Novel dibenzo-24-crown ether substituted nitroxides and their use as spin probes for the detection of cation guests by EPR are reported.

The dynamics induced by quantum tunneling is found to be closely connected to the shape of the potentials for weakly bound complexes.

Inclusion of a heavy gold atom in a peripheral position of BODIPY is enough to promote ISC.

The ground state of He–HCO⁺ is investigated using a recently developed double resonance technique, consisting of a rotational transition followed by a vibrational transition into a dissociative state.

The observed spectrum identifies a C_s symmetry σ-type complex, with the two subunits held together by coplanar “classical” O–H⋯N and weak C–H⋯π intermolecular hydrogen bonds. The O⋯N distance decreases by 4 mÅ upon deuteration of the hydroxyl group (reverse Ubbelohde effect).

Using an accurate 6D water dimer potential energy surface, we compute vibration–rotation-tunnelling levels of HOD dimer, by assuming that the two monomers are rigid.

Aggregation of propofol and benzocaine was explored using mass-resolved laser spectroscopy and DFT calculations.

A route toward the detection of the methyl-cyclopropenyl cation in space: a spectroscopic characterization by state-of-the-art computational approaches.

Computing the energy levels of molecular hydrogen rotating in carbon nanotubes of increasing size.

Vibronic spectra of two BODIPY derivatives were computed using both Time-Independent (TI) and Time-Dependent (TD) formalisms including solvent and temperature effects with several DFT functionals.

Due to the poor prediction of harmonic frequencies, vibrational modes containing C–F stretching motions are often strongly misplaced by common hybrid functionals. Herein we show that M06-2X functional performs exceptionally good in these cases.

State-of-the-art theoretical methods are used to investigate the rotation–vibration spectrum of methyl fluoride.