Pseudopotential periodic hartree-fock study of rutile TiO2

Silvi, Bernard; Fourati, Najla; Nada, R.H.; Catlow, C. Richard A.

doi:10.1016/0022-3697(91)90029-y

Cited by 97 publications

(33 citation statements)

References 22 publications

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“…In Table I, a summary of the results from a selection of experimental and recent ab initio studies of the structural parameters of rutile and anatase is presented. Early HF, 57,58 PW-LDA, [59][60][61][62] and combined HF and DFT studies of rutile 63 yielded lattice parameters to within 2% of experiment. More recent studies that have taken advantage of improvements in the theoretical techniques and available computing power to perform calculations with improved treatments of exchange and correlation ͑DFT calculations based on the GGA͒ ͑Refs.…”

Section: Resultsmentioning

confidence: 99%

First-principles calculations of the phase stability ofTiO2

2002

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First-principles calculations of the crystal structures, bulk moduli, and relative stabilities of seven known and hypothetical TiO 2 polymorphs ͑anatase, rutile, columbite, baddeleyite, cotunnite, pyrite, and fluorite structures͒ have been carried out with the all-electron linear combination of atomic orbitals ͑LCAO͒ and pseudopotential planewave ͑PW͒ methods. The anatase versus rutile relative phase stability at 0 K and zero pressure has been investigated using high-quality basis sets and carefully controlled computational parameters. From the optimal crystal structures obtained with the Hartree-Fock theory at various pressures, the bulk modulus and phase transition pressures of various high-pressure polymorphs have been derived at the athermal limit. In most cases, the calculated unit cell data agree to within 2% of the corresponding experimental determination. Complete predicted structural data ͑unit cell constants and fractional atomic coordinates͒ are presented for the baddeleyite and pyrite forms. The calculated bulk moduli are within 10% of the most reliable experimental results. Both the all-electron LCAO and pseudopotential PW methods predict anatase to be more stable than rutile at 0 K and ambient pressure. The computed anatase-columbite, rutile-columbite, columbite-baddeleyite, and baddeleyite-cotunnite phase transitions appear in the same order as observed in experiments, and the transition pressures agree semiquantitatively with those measured. The pyrite and fluorite structures are predicted to be less stable than other polymorphs at pressures below 70 GPa in agreement with experiments. Finally, the elastic properties, compressibilities and phase transformations of the various polymorphs are discussed in terms of simple models based on the behavior of the constituent Ti-O polyhedra under compression.

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Section: Resultsmentioning

confidence: 99%

First-principles calculations of the phase stability ofTiO2

2002

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“…DFT/B3LYP results are at least as good as those obtained with more sophisticated correlated calculations or perturbation theories [42,43]. Furthermore, DFT/B3LYP approach was also employed in our recent studies on the electronic and structural properties of the bulk and surfaces of SnO 2 [37] and TiO 2 (anatase) [44] The corresponding exponents and coefficients for the valence double-zeta basis set representing the Sn and O centers have already been reported in our previous study [34], while the valence basis set for Ti has been taken from [46]. The band structure was obtained at 80 k points along the appropriate high-symmetry paths of de Brillouin zone for a tetragonal primitive system.…”

Section: Computing Methods and Model Systemmentioning

confidence: 99%

Electronic and structural properties of SnxTi1−xO2 solid solutions: a periodic DFT study

et al. 2003

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The structural and electronic properties of selected compositions of Sn x Ti 1−x O 2 solid solutions (x = 0, 1/24, 1/16, 1/12, 1/8, 1/6, 1/4, 1/2, 3/4, 5/6, 7/8, 11/12, 15/16, 23/24 and 1) were investigated by means of periodic density functional theory (DFT) calculations at B3LYP level. The calculations show that the corresponding lattice parameters vary non-linearly with composition, supporting positive deviations from Vegard's law in the Sn x Ti 1−x O 2 system. Our results also account for the fact that chemical decomposition in Sn x Ti 1−x O 2 system is dominated by composition fluctuations along [0 0 1] direction. A nearly continuous evolution of the direct band gap and the Fermi level with the growing value of x is predicted. Ti 3d states dominate the lower portion of the conduction band of Sn x Ti 1−x O 2 solid solutions. Sn substitution for Ti in TiO 2 increases the oxidation-reduction potential of the oxide as well as it renders the lowest energy transition to be indirect. These two effects can be the key factors controlling the rate for the photogenerated electron-hole recombination. These theoretical results are capable to explain the enhancement of photoactivity in Sn x Ti 1−x O 2 solid solutions.

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“…Analysing the period of defect for the same supercell size (given L-value) in these groups we found that for rutile structure (simple tetragonal lattice, a 4X59 # e, c 2X96 # e) the best choice would be G D D For the unrestricted Hartree-Fock LCAO calculations we used the program Crystal-95 [14,15] and Durand-Barthelat [16] pseudopotentials. The atomic basis functions of Ti and O atoms were taken from [1] which were fitted to reproduce band structure and bonding properties of rutile. The vanadium atom functions were found by fitting these properties of VO 2 crystal.…”

Section: Unrestricted Hartree-fock Lcao Calculations Of V-doped Rutilmentioning

confidence: 99%

Supercell Model of V-Doped TiO2: Unrestricted Hartree-Fock Calculations

Ėvarestov

Smirnov²

1999

phys. stat. sol. (b)

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The host crystal space group and the point defect site symmetry group being given the procedure of generation of the imperfect space group in the supercell or periodic defect model is considered. The approach developed is applied to the symmetry analysis of the possible space groups of metal‐doped rutile and anatase structures in the supercell model. The results of unrestricted Hartree‐Fock calculations of the V‐doped rutile electronic structure (an impurity atom charge, valence states, an impurity level position in the energy gap) are given. Supercells of 36, 60, 84 atoms chosen on the base of the symmetry analysis are calculated. The convergence of the results with the supercell increasing is demonstrated.

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Pseudopotential periodic hartree-fock study of rutile TiO2

Cited by 97 publications

References 22 publications

First-principles calculations of the phase stability ofTiO2

First-principles calculations of the phase stability ofTiO2

Electronic and structural properties of SnxTi1−xO2 solid solutions: a periodic DFT study

Supercell Model of V-Doped TiO2: Unrestricted Hartree-Fock Calculations

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