# _Ab Initio_ Study of the Mechanism of Proton Migration in Perovskite LaScO\({}_{3}\)  
[PERSON]  
1 Institute of High-Temperature Electrochemistry Ural Branch of the Russian Academy of Sciences, 620990 Vekaterinburg, Russia; [EMAIL_ADDRESS] (D.S.P.); [EMAIL_ADDRESS] (Y.P.Z.); [PERSON]ADDRESS] (O.R.R.)2 Institute of Chemical Engineering, Ural Federal University Named after the First President of Russia [PERSON], 620002 Vekaterinburg, Russia 2  
[PERSON]  
1 Institute of High-Temperature Electrochemistry Ural Branch of the Russian Academy of Sciences, 620990 Vekaterinburg, Russia; [EMAIL_ADDRESS] (D.S.P.); [EMAIL_ADDRESS] (Y.P.Z.); [PERSON]_ADDRESS] (O.R.R.)2 Institute of Chemical Engineering, Ural Federal University Named after the First President of Russia [PERSON], 620002 Vekaterinburg, Russia 2  
[PERSON]  
1 Institute of High-Temperature Electrochemistry Ural Branch of the Russian Academy of Sciences, 620990 Vekaterinburg, Russia; [EMAIL_ADDRESS] (D.S.P.); [EMAIL_ADDRESS] (Y.P.Z.); [PERSON]ADDRESS] (O.R.R.)2 Institute of Chemical Engineering, Ural Federal University Named after the First President of Russia [PERSON], 620002 Vekaterinburg, Russia 2  
[PERSON]  
1 Institute of High-Temperature Electrochemistry Ural Branch of the Russian Academy of Sciences, 620990 Vekaterinburg, Russia; [EMAIL_ADDRESS] (D.S.P.); [EMAIL_ADDRESS] (Y.P.Z.); [PERSON]_ADDRESS] (O.R.R.)2 Institute of Chemical Engineering, Ural Federal University Named after the First President of Russia [PERSON], 620002 Vekaterinburg, Russia 2  
Footnote 10: email: {https:humid atmosphere at 800 \({}^{\circ}\)C [8]. Importantly, this result was achieved using materials that do not contain Ba or Sr, which are not suitable for fuel cells operating in a CO\({}_{2}\) atmosphere.  
LaScO\({}_{3}\) perovskite is a promising proton conductor [9; 10; 11; 12]. It exhibits a fairly high structural stability. Even at high impurity levels, LaScO\({}_{3}\) is characterized by orthorhombic symmetry in the range from room temperature to about 1993 K [13]. The structural skeleton of this compound is made up of rigid ScO\({}_{6}\) octahedra. The formation of oxygen vacancies, which increase the proton conductivity, occurs when La is replaced by Sr [14]. The proton conductivity (\(6\times 10^{-3}\) S\(\cdot\)cm\({}^{-1}\)) obtained upon reaching the ratio of Sr to La x = 0.2, i.e., for the La\({}_{0.8}\)Sr\({}_{0.2}\)ScO\({}_{3-8}\) compound, still remains one of the highest [15]. This doped perovskite is a promising proton-conducting electrolyte and can be used in proton-ceramic fuel cells. However, a targeted enhancement of proton conductivity requires a fundamental study of the mechanism of proton migration in the corresponding solid electrolyte. Among the most reliable methods for studying the mechanism of conduction performed at the atomic level are atomistic calculations in combination with neutron diffraction and nuclear magnetic resonance (NMR). The possible implementation of the proton dynamics in a crystal with a perovskite structure has not yet been fully investigated [16].  
We used an ab initio molecular dynamics approach to comprehensively investigate the proton dynamics in a defect-free perovskite LaScO\({}_{3}\) crystal. In this new study, we investigated the influence of initial proton velocities and locations, as well as the influence of electric field and temperature on proton behavior in LaScO\({}_{3}\) perovskite. Carrying out these studies can confirm or refute the hypothesis about the polaron character of proton movement along the perovskite crystal lattice. Doped ceramics LaScO\({}_{3}\) is also promising material for the use as a solid electrolyte in SOFCs.  
The aim of this work is to investigate the mechanism of proton movement in defect-free LaScO\({}_{3}\) perovskite as a function of temperature, magnitude of the applied electric field, initial velocity of the proton, and its primary location.