Bulk properties and electronic structure of SrTiO3, BaTiO3, PbTiO3 perovskites: an ab initio HF/DFT study

Calculations for antiferrodistortive phase of SrTiO3perovskite: hybrid density functional study

“…1.004 [17]). Simultaneously, these DFT calculations significantly underestimate the bandgap (typically, <2 eV, instead of experimental 3.3 eV) [17][18][19][20][21]. Surprisingly, an important question, how octahedral rotation affects the electronic bands and optical properties, has not been discussed so far, except for a single old paper [7].…”

“…The following BSs were constructed and optimized: 8-411(1d)G for O, 411(311d)G for Ti and 311(1d)G for Sr, where the numbers refer to the contraction level. Further details are available from [21].…”

“…In our previous simulations of perovskites [21] we used to shift up the energies of the conduction bands (level shift) in order to accelerate convergence of the density matrix and to ensure its stability. This is a common practice in such calculations.…”

“…Here we applied the basis set recently developed specially for STO [21]. In these simulations we replaced nuclei and inner core electrons of Sr and Ti atoms with 'small-core' Hay-Wadt effective core potentials [24].…”

First-Principles Modeling of SrTiO3Based Oxides for Thermoelectric Applications

“…The electronic structure calculations have been performed using the linear combination of atomic orbitals method as implemented in CRYSTAL first-principles code. [73] We used localized Gaussian-type basis sets including polarization orbitals and considered all the electrons for Ti [74], O [75], V [78], K and Nb [76], F and Co [77]. The Hartree-Fock pseudopotential for Sr [75], and the Stuttgart energy-consistent pseudopotential for La [79] were used.…”