Structural and lattice dynamical properties of Zintl NaIn and NaTl compounds

► NaTl and NaIn are crystalline in B32 phase like the most of the technologically important I-III compounds. ► The structural phase transition pressures from B32 to B2 structure for NaIn and NaTl are found to be 114.2 and 43.9 GPa for NaIn and NaTl, respectively. ► Also, the lattice dynamical and the thermo dynamical properties of NaIn and NaTl in B32 phase are reported.