Density functional investigation of the thermophysical and thermochemical properties of talc [Mg3Si4O10(OH)2]

Ulian, Gianfranco; Valdrè, Giovanni

doi:10.1007/s00269-014-0708-7

Cited by 32 publications

(30 citation statements)

References 39 publications

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“…However, the entity of the Pulay forces depends on the system under consideration. For example, in previous works that considered solid phases with mixed covalent bonding and dispersive interactions the results obtained with B3LYP and GTO basis sets were in good agreement with experimental data.…”

Section: Resultssupporting

confidence: 79%

“…On one hand, this could be due to the athermal conditions, which cause the unit cell shrinking ( vide supra ) and consequently an increase in SOEC components. It was proved that including temperature in the simulations, for example, by using the quasi‐harmonic approximation, led to better agreement between theoretical and experimental results on the structural and mechanical properties of phyllosilicates . Mineral stiffness is inversely proportional to temperature and, if this variable is included in the simulation, it is supposed to be lower than that obtained in athermal conditions.…”

Section: Resultsmentioning

confidence: 98%

“…This particular DFT method is called B3LYP‐D*. The same approach has been adopted with good results in previous works on phyllosilicates, where dispersive forces are dominant …”

Section: Methodsmentioning

confidence: 99%

“…In the last decade, many computational chemistry researches were aimed to investigate the mechanical properties of several solid phases, at both athermal [3][4][5][6][7][8] and thermal conditions. [9][10][11][12][13] When dealing with condensed matter, periodic boundary conditions (PBC) are usually chosen due to the possibility to deal with real infinite systems. Within this framework, the wave function of a finite unit cell is replicated in the space according to the system type (bulk, surface, or rod/ polymer), accounting for all short and long range interactions that take place in a real solid.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Second‐order elastic constants of hexagonal hydroxylapatite (P6₃) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Ulian

Valdrè

2017

Int J of Quantum Chemistry

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Three very popular Hamiltonians in the density functional theory framework, PBE, PBEsol, and B3LYP, and different basis sets (Gaussian‐type orbitals and plane waves) were employed to simulate the hydroxylapatite unit cell and its second‐order elastic constants. Dispersive interactions were included in the quantum‐mechanical treatment via the DFT‐D2 and Tkatchenko‐Scheffler schemes. The calculated bulk, shear, and Young's moduli were in the range of 82‐117 GPa, 42‐51 GPa, and 107‐134 GPa, respectively. The axial moduli, Ka and Kb, were instead in the range of 277‐322 GPa and 506‐509 GPa. The theoretical data, especially those from plan waves simulations, are in good agreement with available results in literature and further extend the knowledge of the mechanical and vibrational properties of hydroxylapatite.

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Section: Resultssupporting

confidence: 79%

Section: Resultsmentioning

confidence: 98%

“…This particular DFT method is called B3LYP‐D*. The same approach has been adopted with good results in previous works on phyllosilicates, where dispersive forces are dominant …”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Second‐order elastic constants of hexagonal hydroxylapatite (P6₃) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Ulian

Valdrè

2017

Int J of Quantum Chemistry

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“…The talc crystal is a natural soft magnesium silicate mineral, with chemical formula Mg 3 Si 4 O 10 (OH) 2 , obtained from a soapstone mine in Ouro Preto, Brazil . This vdW crystal forms, by mechanical exfoliation, flat crystals with nanometer thicknesses, as observed with AFM topography (Figure b).…”

Section: Hybrid Polaritons In Graphene‐talc 2d Heterostructuresmentioning

confidence: 93%

Probing Polaritons in 2D Materials with Synchrotron Infrared Nanospectroscopy

Barcelos

Bechtel

Matos

et al. 2019

Advanced Optical Materials

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Polaritons, which are quasiparticles composed of a photon coupled to an electric or magnetic dipole, are a major focus in nanophotonic research of van der Waals (vdW) crystals and their derived 2D materials. For the variety of existing vdW materials, polaritons can be active in a broad range of the electromagnetic spectrum (meVs to eVs) and exhibit momenta much higher than the corresponding free‐space radiation. Hence, the use of high momentum broadband sources or probes is imperative to excite those quasiparticles and measure the frequency‐momentum dispersion relations, which provide insights into polariton dynamics. Synchrotron infrared nanospectroscopy (SINS) is a technique that combines the nanoscale spatial resolution of scattering‐type scanning near‐field optical microscopy with ultrabroadband synchrotron infrared radiation, making it highly suitable to probe and characterize a variety of vdW polaritons. Here, the advances enabled by SINS on the study of key photonic attributes of far‐ and mid‐infrared plasmon‐ and phonon‐polaritons in vdW and 2D crystals are reviewed. In that context the SINS technique is comprehensively described and it is demonstrated how fundamental polaritonic properties are retrieved for a range of atomically thin systems including hBN, MoS2, graphene and 2D heterostructures.

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First principle investigation of the thermomechanical properties of type A carbonated apatite

Ulian

Valdrè

2019

Int J of Quantum Chemistry

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Calcium apatites with the general chemical formula (Ca, X) 10 (PO 4 , Y) 6 Z 2 represent a mineral family of utmost importance in several fields, for example, bone biology, biomaterials, and mineralogy. However, few works have focused on the mechanical properties of these phases, and in particular, no data are available on the thermomechanical and thermodynamic properties of carbonate-bearing (hydroxyl)apatites. In the present work, the equation of state of type A carbonated apatite (CAp, Ca 10 (PO 4 ) 6 CO 3 , space group P1) was calculated by ab initio quantum mechanical methods within the density functional theory (DFT) framework. Starting from athermal results (at 0 K), the combined effect of temperature and pressure was investigated through the quasiharmonic approximation (QHA). In athermal conditions, the equation of state of the CAp unit cell volume can be described by a third-order Birch-Murnaghan formulation, with parameters V 0 = 538.14(5) Å 3 , K 0 = 106.2(7) GPa, and K 0 = 4.6(4). The QHA well described the temperature and pressure dependence of the thermodynamics and mechanical properties of the mineral. For instance, the bulk modulus at 0 GPa and ambient temperature (300 K) is K T0 = 102.95 GPa, which is lower than that of stoichiometric apatite by about 6%. The unit cell thermal expansion coefficient between 0 and 600 K was also calculated and reported. The results are in line with the few available experimental data reported in literature on type AB carbonated hydroxylapatite. The reported findings further extend the knowledge of the mechanical and thermal behaviors of this important mineral found in biological environments, results that are useful for biotechnological and other applications of the (C)OHAp phases. K E Y W O R D S bone mineralogy, carbonated apatite, DFT, Gaussian-type orbitals, quasiharmonic approximation

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Density functional investigation of the thermophysical and thermochemical properties of talc [Mg3Si4O10(OH)2]

Cited by 32 publications

References 39 publications

Second‐order elastic constants of hexagonal hydroxylapatite (P6₃) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Second‐order elastic constants of hexagonal hydroxylapatite (P6₃) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Probing Polaritons in 2D Materials with Synchrotron Infrared Nanospectroscopy

First principle investigation of the thermomechanical properties of type A carbonated apatite

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Density functional investigation of the thermophysical and thermochemical properties of talc [Mg3Si4O10(OH)2]

Cited by 32 publications

References 39 publications

Second‐order elastic constants of hexagonal hydroxylapatite (P63) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Second‐order elastic constants of hexagonal hydroxylapatite (P63) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Probing Polaritons in 2D Materials with Synchrotron Infrared Nanospectroscopy

First principle investigation of the thermomechanical properties of type A carbonated apatite

Contact Info

Product

Resources

About

Second‐order elastic constants of hexagonal hydroxylapatite (P6₃) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets

Second‐order elastic constants of hexagonal hydroxylapatite (P6₃) fromab initioquantum mechanics: Comparison between DFT functionals and basis sets