Electronic structure 53 Electronic.structure 23 Density functional theory 21 Calculations 17 Energy gap 8 First principles 7 Quantum chemistry 7 electronic structure 7 Computation theory 6 Electronic properties 6 Optical properties 6 density functional theory 6 Atoms 5 Binary alloys 5 Chemical bonds 5 Electronic structure theory 5 Perturbation techniques 5 Phonons 5 Quantum Theory 5 Two-dimensional 5 quantum theory 5 Ab initio electronic structure methods 4 Antiferromagnetism 4 Crystal structure 4 Density-functional-theory 4 Dynamics 4 Excited states 4 Ground state 4 Magnetic moments 4 Molecules 4