The Ag–Li system's experimental and ab initio thermodynamic dataset

The Ag–Li system was analysed using first-principles calculations 10.1016/j.jallcom.2019.152811 [1]. The method included using density functional theory to optimize the crystal structure of the phases constituting the binary phase diagram by relaxing atomic positions, volume, and shape. The optimized structures were subsequently used to calculate thermodynamic properties at different temperatures; by determining the zero-point energy, the vibrational internal energy, and the entropy, the heat capacity at constant volume was obtained as well as the phases' stability limits. Furthermore, optimized structures were used to calculate the XRD patterns and to compare them with experimental data. All the referred data are now accessible to researchers and industrials demanding to work with binary and higher-order systems that include Ag and Li, for example, for energy storage. Binaries should be well assessed prior to higher-order phase diagrams and in that resides additional usefulness to this data.


Data
1 -Ag30Li70-experimental-XRD.txt X-ray diffraction pattern for the Ag 30 Li 70 alloy, including settings on the experimental run, followed by two columns with the 2q( ) and Intensity(a.u.) normalized to an I max ¼ 100. No zero-shift correction and no normalization were performed. The configuration of the diffractometer is Bragg-Brentano and the sample was polycrystalline. The source used was CuKa.
2 -Ag4Li9-gamma-disordered-calculated-XRD.txt X-ray diffraction simulated pattern constituted by two columns with 2q( ) and Intensity(a.u.) normalized to I max ¼ 100 for the g-Ag 4 Li 9 disordered phase. The simulated source used was CuKa.
Specifications Table   Subject Metals and Alloys Specific subject area Experimental and calculated Thermodynamic and structural data for the assessment of the AgeLi system with applications in energy storage and high-temperature solders Type of data The experimental structural XRD data were obtained using a CuKa radiation source. The calculated data were obtained using a plane wave cut-off of at least 400.00 eV and kspacings of 0.230 Â 0.230 Â 0.230 Å À1 Description of data collection The XRD data were obtained with a Bragg Brentano configuration for polycrystalline samples with a wavelength of l ¼ 0.1542 nm.
The calculated data were obtained by building the crystal structure of the phase and optimizing it using VASP and allowing structure, volume, and atomic sites to relax and then, in a subsequent run, using MT or phonon to obtain the Thermodynamic properties vs temperature. Value of the Data These data are useful for the research and for the industry related to energy storage materials and high temperature solders The crystallography and CALPHAD researchers will benefit from these data; the latter because they need experimental and ab initio data to assess binary and higher-order phase diagrams The phase diagram needs to be reassessed and the experimental data are scarce since high reactivity of lithium at elevated temperature with the air contained elements (O 2 , N 2 , H 2 O) and the high energy effects accompanying the respective reactions makes it very difficult to obtain good quality results, therefore, the calculated data provides new insights for samples preparation and experimental planification 3 -Ag3Li10_gamma_disordered_calculated-XRD.txt X-ray diffraction simulated pattern constituted by two columns with 2q( ) and Intensity(a.u.) normalized to I max ¼ 100 for the g-Ag 3 Li 10 disordered phase. The simulated source used was CuKa.
4 -Ag15Li49-beta-calculated-XRD.txt X-ray diffraction simulated pattern constituted by two columns with 2q( ) and Intensity(a.u.) normalized to I max ¼ 100 for the b-Ag 15 Li 49 phase. The simulated source used was CuKa.
5 -Ag4Li9-gamma-disordered-calculated-Cv.txt Calculated vibrational heat capacity at constant volume for temperatures below the melting point T < 500 K for the g-Ag 4 Li 9 disordered phase that was optimized using DFT. The melting point is not known with precision. Two columns with the data: T(K), and Cv(J.K À1 mol À1 ) included.
6 -Ag4Li9-gamma-disordered-calculated-alpha.txt Calculated thermal linear expansion coefficient for g-Ag 4 Li 9 disordered phase for temperatures below the melting point T < 500 K. The melting point is not known with precision. Two columns with the data: T(K), and a(K À1 ) Â 10 6 included.
Calculated enthalpies of formation, H f , for several phases (stable and unstable) at 600 K. Three columns: compound(stoichiometry), x(Li), and H f (kJ.mol of atoms À1 ) included.
14 e Table 1 Details on AgeLi phases' composition, structures and optimization methods (compound, x(Li), initial structure space group, and method to obtain the final optimized structure).

Experimental design, materials, and methods
The Ag 30 Li 70 sample was prepared as described in Ref. [1]. The XRD data were obtained from 10 to 90 (2q) with a Bragg Brentano configuration for polycrystalline samples with a wavelength of l ¼ 0.1542 nm which is, in fact, an average of two closely spaced peaks (CuKa1 and CuKa2).
The theoretical background in Ref. [1] explains the calculations of the Thermodynamic data included in this database; the theoretical principles were used as implemented in VASP [2], MT [3] and Phonon [4].
Each phase was optimized from a structure that was obtained using random substitution, special quasirandom structure (SQS), or substitutional search, depending on the type of structure (e.g. fcc or bcc). Since SQS's mimics well the local atomic structure of the random alloy, their electronic properties, calculable via first-principles techniques, provide a representation of the electronic structure of the alloy [5]. Table 1 shows the stoichiometry of the compound, the initial space group, and the method used for obtaining the compounds whose thermodynamic data is included in the dataset associated with this work.