Piezo crystals including quartz, quartz-like crystals, known and novel crystals of langasite-type structure were treated with density-functional perturb theory (DFPT) using plane-wave pseudopotentials method, within t...Piezo crystals including quartz, quartz-like crystals, known and novel crystals of langasite-type structure were treated with density-functional perturb theory (DFPT) using plane-wave pseudopotentials method, within the local density approximation (LDA) to the exchange-correlation functional. Compared with experimental results, the ab initio calculation results have quantitative or semi-quantitative accuracy. It is shown that first principle calculation opens a door to the search and design of new piezoelectric material. Further application of first principle calculation to forecast the whole piezoelectric properties was also discussed.展开更多
First principle calculation within the Density Functional Theory (DFT) and Density Functional Perturbation Theory (DFPT) using Local Density Approximation as implemented in Quantum ESPRESSO has been significantly used...First principle calculation within the Density Functional Theory (DFT) and Density Functional Perturbation Theory (DFPT) using Local Density Approximation as implemented in Quantum ESPRESSO has been significantly used to investigate the structural and Piezoelectric, properties of Perovskite ZrTi(PbO3)2. From structural properties calculation, the ground state total energy of -2417.12 eV has been obtained which led to an equilibrium lattice constant of a= 5.620Åfor ZrTi(PbO3)2. Our obtained optimized atomic positions and atomic effective charge shows that the optimized ZrTi(PbO3)2 is stable and the Piezoelectric stress tensor is calculated using Berry-phase approach within density functional perturbation theory (DFPT). From our calculation, we have obtained the stress tensor elements with values of d1,5 = 6.81, d3,1 = 1.69, and d3,3 = 6.18, which is in agreement with the values obtained for tetragonal PbTiO3.展开更多
Verification and validation of methods and first-principles software are at the core of computational solid-state physics but are too rarely addressed.We compare four first-principles codes:ABINIT,Quantum ESPRESSO,EPW...Verification and validation of methods and first-principles software are at the core of computational solid-state physics but are too rarely addressed.We compare four first-principles codes:ABINIT,Quantum ESPRESSO,EPW,ZG,and three methods:(i)the Allen-Heine-Cardona theory using density functional perturbation theory(DFPT),(ii)the Allen-Heine-Cardona theory using Wannier function perturbation theory(WFPT),and(iii)an adiabatic non-perturbative frozen-phonon method.For these cases,we compute the real and imaginary parts of the electron-phonon self-energy in diamond and BAs,including dipoles and quadrupoles when interpolating.We find excellent agreement between software that implements the same formalism as well as good agreement between the DFPT and WFPT methods.Importantly,we find that the Deybe-Waller term is momentum dependent which impacts the mass enhancement,yielding approximate results when using the Luttinger approximations.Finally,we compare the electron-phonon spectral functions between ABINIT and EPW and find excellent agreement even away from the band edges.展开更多
基金Project supported by the National Natural Science Foundation of China (50242007) and Shanghai Supercomputing Center through Supplying Computational Time
文摘Piezo crystals including quartz, quartz-like crystals, known and novel crystals of langasite-type structure were treated with density-functional perturb theory (DFPT) using plane-wave pseudopotentials method, within the local density approximation (LDA) to the exchange-correlation functional. Compared with experimental results, the ab initio calculation results have quantitative or semi-quantitative accuracy. It is shown that first principle calculation opens a door to the search and design of new piezoelectric material. Further application of first principle calculation to forecast the whole piezoelectric properties was also discussed.
文摘First principle calculation within the Density Functional Theory (DFT) and Density Functional Perturbation Theory (DFPT) using Local Density Approximation as implemented in Quantum ESPRESSO has been significantly used to investigate the structural and Piezoelectric, properties of Perovskite ZrTi(PbO3)2. From structural properties calculation, the ground state total energy of -2417.12 eV has been obtained which led to an equilibrium lattice constant of a= 5.620Åfor ZrTi(PbO3)2. Our obtained optimized atomic positions and atomic effective charge shows that the optimized ZrTi(PbO3)2 is stable and the Piezoelectric stress tensor is calculated using Berry-phase approach within density functional perturbation theory (DFPT). From our calculation, we have obtained the stress tensor elements with values of d1,5 = 6.81, d3,1 = 1.69, and d3,3 = 6.18, which is in agreement with the values obtained for tetragonal PbTiO3.
基金supported by the Fonds de la Recherche Scientifique-FNRS under Grants number T.0183.23(PDR)and T.W011.23(PDR-WEAVE)supported by the Walloon Region in the strategic axe FRFS-WEL-T.J.-M.L.and C.-H.P.acknowledge support from Korean-NRF No-2023R1A2C1007297+1 种基金Computational resources have been provided by the PRACE award granting access to MareNostrum4 at Barcelona Supercomputing Center(BSC),Spain and Discoverer in SofiaTech,Bulgaria(OptoSpin project id.2020225411)by the Consortium desÉquipements de Calcul Intensif(CÉCI),funded by the FRS-FNRS under Grant No.2.5020.11 and by the Walloon Region,as well as computational resources awarded on the Belgian share of the EuroHPC LUMI supercomputer.
文摘Verification and validation of methods and first-principles software are at the core of computational solid-state physics but are too rarely addressed.We compare four first-principles codes:ABINIT,Quantum ESPRESSO,EPW,ZG,and three methods:(i)the Allen-Heine-Cardona theory using density functional perturbation theory(DFPT),(ii)the Allen-Heine-Cardona theory using Wannier function perturbation theory(WFPT),and(iii)an adiabatic non-perturbative frozen-phonon method.For these cases,we compute the real and imaginary parts of the electron-phonon self-energy in diamond and BAs,including dipoles and quadrupoles when interpolating.We find excellent agreement between software that implements the same formalism as well as good agreement between the DFPT and WFPT methods.Importantly,we find that the Deybe-Waller term is momentum dependent which impacts the mass enhancement,yielding approximate results when using the Luttinger approximations.Finally,we compare the electron-phonon spectral functions between ABINIT and EPW and find excellent agreement even away from the band edges.
