Polymorphism of Resorcinol Explored by Complementary Vibrational Spectroscopy (FT-RS, THz-TDS, INS) and First-Principles Solid-State Computations (Plane-Wave DFT)

Abstract

The polymorphism of resorcinol has been complementary studied by combining Raman, time-domain terahertz, and inelastic neutron scattering spectroscopy with modern solid-state density functional theory (DFT) calculations. The spectral differences, emerging from the temperature-induced structural phase transition, have been successfully interpreted with an emphasis on the low-wavenumber range. The given interpretation is based on the plane-wave DFT computations, providing an excellent overall reproduction of both wavenumbers and intensities and revealing the source of the observed spectral differences. The performance of the generalized gradient approximation (GGA) functionals in prediction of the structural parameters and the vibrational spectra of the normal-pressure polymorphs of resorcinol has been extensively examined. The results show that the standard Perdew, Burke, and Ernzerhof (PBE) approach along with its "hard" revised form tends to be superior if compared to the "soft" GGA approximation.

Experimental (X-ray, 13C CP/MAS NMR, IR, RS, INS, THz) and Solid-State DFT Study on (1:1) Co-Crystal of Bromanilic Acid and 2,6-Dimethylpyrazine

“…Similarly, one can observe a slightly different performance of PBE and PW91, which are conceptually recognized as nearly equivalent. As expected, 51 the worst description of the cell parameters was found with "hard" rPBE.…”

“…51 Here, we would like to further extend the analysis into the influence of the vdW corrections on the vibrational properties of the studied system.…”

Vibrational Response of Felodipine in the THz Domain: Optical and Neutron Spectroscopy Versus Plane-Wave DFT Modeling

“…Exchange and correlation were approximated with a generalized gradient approximation (GGA)-type functional from Perdew-Burke-Ernzerhof [29]. We have earlier proven such a strategy to be robust for the prediction of the terahertz spectra for complex molecular systems [30][31][32][33], including similar drug, Lacidipine [34]. Furthermore, the use of the room temperature cell volume was dictated by an occurrence of some discrepancies in phonon predictions when using the fully relaxed cell parameters [25], indicating a non-negligible influence of the temperature and calling for accounting for the cell expansion.…”

“…While introducing the use of the analytical response scheme by Gonze and Baroni [37][38][39][52][53][54][55], this paper provides a proven numerical recipe for an accurate modeling of low-wavenumber phonon frequencies. This strategy has been followed with a number of examples presented in the literature, using CASTEP [30][31][32][33][105][106][107][108][109], QUAN-TUM ESPRESSO [106,[110][111][112][113][114], ABINIT [115][116][117], or VASP [118,119], and has been used in the present study. Instead of advocating any of the presented strategies, we further highlight the main differences and limitations of each approach as both have their pros and cons.…”

Vibrational Dynamics of Crystalline 4-Phenylbenzaldehyde from INS Spectra and Periodic DFT Calculations

“…The use of periodic density functional calculations (periodic DFT) to address the vibrational spectra of molecular crystals is becoming increasingly popular [1][2][3][4][5][6][7][8][9][10][11][12]. In fact, the periodic DFT approach, although originally developed to deal with extended inorganic systems, was found to be highly efficient in predicting the vibrational spectra of molecular crystals [13].…”