CRYSTAL: a computational tool for the <i>ab initio</i> study of the electronic properties of crystals

Dovesi, Roberto; Orlando, Roberto; Civalleri, Bartolomeo; Roetti, C.; Saunders, V. R.; Zicovich‐Wilson, Claudio M.

doi:10.1524/zkri.220.5.571.65065

Cited by 975 publications

(990 citation statements)

References 30 publications

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“…First-principles solid-state DFT calculations were performed within the Linear Combination of Atomic Orbital (LCAO) scheme with the CRYSTAL09 Code [50,51] and the Generalized Gradient Approximation (GGA) scheme with the QuantumEspresso Package [52]. The calculation of the hyperfine properties was performed in CRYS-TAL09 as previous studies [12,53] have shown that the use of hybrid functionals in an all-electron treatment provides good agreement with experiments.…”

Section: Methodsmentioning

confidence: 99%

DFT investigation of the effect of spin-orbit coupling on the NMR shifts in paramagnetic solids

et al. 2017

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Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful tool for studying the structural and electronic properties of paramagnetic solids. However, the interpretation of paramagnetic NMR spectra is often challenging as a result of the interactions of unpaired electrons with the nuclear spins of interest. In this work, we extend the formalism of the paramagnetic NMR shielding in the presence of spin-orbit coupling towards solid systems with multiple paramagnetic centres. We demonstrate how the single-ion Electron Paramagnetic Resonance (EPR) g-tensor is defined and calculated in periodic paramagnetic solids. We then calculate the hyperfine tensor and the g-tensor with density functional theory (DFT) to show the validity of the presented model and we further demonstrate how these interactions can be combined to give the overall paramagnetic shielding tensor, σ s . The method is applied to a series of olivine-type LiTMPO4 materials (with TM=Mn, Fe, Co and Ni) and the corresponding 7 Li and 31 P NMR spectra are simulated. We analyse the effects of spin-orbit coupling and of the electron-nuclear magnetic interactions on the calculated NMR parameters. A detailed comparison is presented between contact and dipolar interactions across the LiTMPO4 series, in which the magnitudes and signs of the non-relativistic and relativistic components of the overall isotropic shift and shift anisotropy are computed and rationalized.

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Section: Methodsmentioning

confidence: 99%

DFT investigation of the effect of spin-orbit coupling on the NMR shifts in paramagnetic solids

et al. 2017

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“…All calculations were carried out by using the periodic ab initio code CRYSTAL09. 29,30 All the SCF calculations and geometry optimizations were performed in P1 group symmetry using the B3LYP-D2* density functional method, which includes an empirical a posteriori correction term proposed by Grimme 26 to account for dispersion forces (missed in the pure B3LYP 31 method), but whose initial parameterization (D2) was modified for extended systems (D2*), 27 to provide accurate results for the calculations of cohesive energies of molecular crystals and of adsorption processes within a periodic treatment. [23][24][25] Moreover, for the adsorption of one H atom, single point energy calculations using the PBE, 32 BLYP, 33,34 and BHLYP 35 density functional methods at the B3LYP-D2* optimized geometries have also been performed in order to check the influence of the method on the computed adsorption energies.…”

Section: Methodsmentioning

confidence: 99%

Interstellar H adsorption and H₂formation on the crystalline (010) forsterite surface: a B3LYP-D2* periodic study

Navarro‐Ruiz

Sodupe

Ugliengo

et al. 2014

Phys. Chem. Chem. Phys.

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The physisorption/chemisorption of atomic hydrogen on a slab model of the Mg2SiO4 forsterite (010) surface mimicking the interstellar dust particle surface has been modeled using a quantum mechanical approach based on periodic B3LYP-D2* density functional calculations (DFT) combined with flexible polarized Gaussian type basis sets, which allows a balanced description of the hydrogen/surface interactions for both minima and attachment of H at the surface at 100 K, but prevents the same process to occur at 10 K.From this H-chemisorbed state, second hydrogen chemisorption mainly occurs on the neighboring Mg ion, thus forming a Mg-H surface group, giving rise to a surface species stabilized by favorable electrostatic interactions between the OH + /H -Mg pair. The formation of molecular hydrogen at the (010) forsterite surface adopting a LangmuirHinshelwood mechanism takes place either starting from two physisorbed H atoms with an almost negligible kinetic barrier through a spin-spin coupling driven reaction or from two chemisorbed H atoms with a barrier surmountable already at T higher than 10 K. We also suggest that a nanosized model of the interstellar dust built from a replica of the forsterite unit cell is able to adsorb half the energy released by the H2 formation by increasing its temperature by about 50 K which could then radiates in about 0.02 s.

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“…For both crystal structures, the P21/n 7 of the dihydrate and Pnma 23 of sesquihydrate partial optimization of atomic positions with fixed cell parameters were performed first using density functional theory as implemented in CRYSTAL09 program 24 The convergence criteria for energy during geometry optimization was set to 10 -7 Hartree, whereas for calculation of vibrations it was 10 -10 Hartree. Extra large grid was used.…”

Section: Computational Detailsmentioning

confidence: 99%

Evidence of Polaron Excitations in Low Temperature Raman Spectra of Oxalic Acid Dihydrate

2016

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Low temperature Raman spectra of oxalic acid dihydrate (8K -300 K) both for polycrystalline and single crystal phase show strong variation with temperature in the interval from 1200 to 2000 cm -1 . Previous low temperature diffraction studies all confirmed the stability of the crystal P21/n phase with no indications of any phase transition, reporting the existence of a strong hydrogen bond between the oxalic acid and a water molecule. A new group of Raman bands in the 1200 -1300 cm -1 interval below 90 K is observed, caused by possible loss of the centre of inversion.This in turn could originate either due to disorder in hydroxyl proton positions, or due to proton transfer from carboxylic group to water molecule. The hypothesis of proton transfer is further supported by the emergence of new bands centered at 1600 cm -1 and 1813 cm -1 , which can be explained with vibrations of H3O + ions. The broad band at 1600 cm -1 looses intensity, while the band at 1813 cm -1 gains intensity on cooling. The agreement between quantum calculations of vibrational spectra and experimentally observed Raman bands of hydronium ions in oxalic acid sesquihydrate crystal corroborate this hypothesis.

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CRYSTAL: a computational tool for the ab initio study of the electronic properties of crystals

Cited by 975 publications

References 30 publications

DFT investigation of the effect of spin-orbit coupling on the NMR shifts in paramagnetic solids

DFT investigation of the effect of spin-orbit coupling on the NMR shifts in paramagnetic solids

Interstellar H adsorption and H₂formation on the crystalline (010) forsterite surface: a B3LYP-D2* periodic study

Evidence of Polaron Excitations in Low Temperature Raman Spectra of Oxalic Acid Dihydrate

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CRYSTAL: a computational tool for the ab initio study of the electronic properties of crystals

Cited by 975 publications

References 30 publications

DFT investigation of the effect of spin-orbit coupling on the NMR shifts in paramagnetic solids

DFT investigation of the effect of spin-orbit coupling on the NMR shifts in paramagnetic solids

Interstellar H adsorption and H2formation on the crystalline (010) forsterite surface: a B3LYP-D2* periodic study

Evidence of Polaron Excitations in Low Temperature Raman Spectra of Oxalic Acid Dihydrate

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Interstellar H adsorption and H₂formation on the crystalline (010) forsterite surface: a B3LYP-D2* periodic study