Quantum ESPRESSO is an integrated suite of Open-Source computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials. Quantum ESPRESSO has evolved into a distribution of independent and inter-operable codes in the spirit of an open-source project. The QuantumESPRESSO distribution consists of a “historical” core set of packages and a set of plu