Q. What is QE(Quantum Espresso)?

A. Quantum Espresso (QE) is an open-source software package for research on the electronic structure and properties of materials at the atomic level. It is primarily based on Density Functional Theory (DFT) and supports both plane-wave and pseudopotential methods.
QE allows researchers to predict and analyze various physical and chemical properties of materials, including their electronic structure, energy, forces, and stresses.