First‐principles density functional theory was used to carefully study the structural, electrical, magnetic, optical, and thermoelectric properties of A 2 MnCl 6 (A = Rb, Cs) double perovskites. To attain high precision, calculations were carried out inside the full‐potential linearized augmented plane wave framework using the Perdew Burke Ernzerhof‐GGA and Tran–Blaha modified Becke–Johnson (potential) (TB‐mBJ) exchange–correlation techniques. Thermodynamic viability is confirmed by the structural stability of both compounds and their negative cohesive and formation energies. The materials’ flat bands close to the Fermi level and direct band gap p‐type semiconducting activity increase their potential for thermoelectric applications. According to the Slater–Pauling rule, ferromagnetism results from the Mn–Cl–Mn superexchange interaction, whereas the hybridization strength and magnetic exchange are slightly altered by Cs substitution. Optoelectronic devices show potential due to their high dielectric constants and strong UV absorption.
Kumbhakar et al. (Wed,) studied this question.