Related papers: The physics of dynamical atomic charges: the case …
The Born effective charge, Z*, that describes the polarization created by collective atomic displacements, can be computed from first-principles following different techniques. We establish the connections existing between these different…
Born effective charge (BEC), a fundamental quantity in lattice dynamics and ferroelectric theory, provides a quantitative measure of linear polarization response to ionic displacements. However, it does not account for higher-order effects,…
In insulators, Born effective charges describe the electrical polarization induced by the displacement of individual atomic sublattices. Such a physical property is at first sight irrelevant for metals and doped semiconductors, where the…
We investigate the chemical bonding characteristics of the transition metal dichalcogenides based on their static and dynamical atomic charges within Density Functional Theory. The dynamical charges of the trigonal transition metal…
Born dynamical charges ($\textbf{Z}^\text{dyn}$) play a key role in the lattice dynamics of most crystals, including both insulators and metals in the nonadiabatic ("clean") regime. Very recently, the so-called static Born charges,…
Most d^0 transition metal (TM) oxides exhibit anomalously large Born dynamical charges associated with off-centering or motion of atoms along the TM-O chains. To understand their chemical origin, we introduce "Wannier Orbital Overlap…
In this study, we present the results of our first-principles calculations of the band structure, density of states and the Born effective charge tensors for the ferroelectric (ground state B1a1) and paraelectric (I4/mmm) phases of bismuth…
The Born effective charge, Z*, that describes the polarization created by collective atomic displacements, can be computed from first-principles by different techniques. Its band-by-band decomposition appeared recently as a powerful tool…
For the orthorhombic intermetallic semiconductor Al$_2$Ru, the bandstructure, valence charge density, zone center optical phonon frequencies, and Born effective charge and electronic dielectric tensors are calculated using variational…
Large values of Born effective charges are generally considered as reliable indicators of the genuine tendency of an insulator towards ferroelectric instability. However, these quantities can be very much influenced by strong electron…
The phonon dispersion curves of cubic BaTiO_3 have been computed within a first-principles approach and the results compared to the experimental data. The curves obtained are very similar to those reported for KNbO_3 by Yu and Krakauer…
We calculate ab-initio the electronic states and the Born dynamical charge Z* of the alkaline-earth oxides in the local-density approximation. We investigate the trend of increasing Z* values through the series, using band-by-band…
We compute for the first time a complete charge analysis (Bader and Born effective) on $X_3^{2+}$Bi$^{3-}$N$^{3-}$ ($X$=Ca,Sr,Ba). The crystals show a great electron sharing with little possibility of ferroelectricity. $Inverse$ perovskites…
Long-range interactions and electric response are essential for accurate modeling of condensed-phase systems, but capturing them efficiently remains a challenge for atomistic machine learning. Traditionally, these two phenomena can be…
Understanding ionic behaviour under external electric fields is crucial to develop electronic and energy-related devices using ion transport. In this study, we propose a neural network (NN) model to predict the Born effective charges of…
The average ionization state is a critical parameter in plasma models for charged particle transport, equation of state, and optical response. The dynamical or nonadiabatic Born effective charge (NBEC), calculated via first principles…
The ferroelectric trends of rutile (TiO$_2$) in bulk and at the (110) surface are investigated by means of ab initio density functional theory. We discuss the underlying mechanism of the incipient ferroelectric behavior of rutile in terms…
First-principles calculations were performed to investigate the ferroelectric properties of barium titanate and bismuth ferrite, as well as phonon dispersion of BaTiO3, using density functional theory and density functional perturbation…
The Born effective charges of component atoms and phonon spectra of a tetrahedrally coordinated crystalline ice are calculated from the first principles method based on density functional theory within the generalized gradient approximation…
We investigate the charge density distribution in titanium dioxide, molecular titanium complexes and a variety of periodic titanium compounds using delocalization indices and Bader charge analysis. Our results are in agreement with previous…