Explore an innovative approach to simulating strongly correlated materials in this 53-minute lecture by Prof. Tsung-Han Lee from National Chung Cheng University. Delve into the rotationally-invariant slave-boson (RISB) method and its combination with density functional theory (DFT+RISB) for studying strong correlation effects. Discover the limitations of RISB's accuracy and learn about the ghost-rotationally-invariant slave-boson (g-RISB) method, which introduces auxiliary ghost orbitals to enhance precision. Examine case studies of transition metal oxides where DFT+RISB requires unrealistic Coulomb parameters, and see how DFT+g-RISB offers a systematic solution for accurate material descriptions using realistic interactions. Compare the accuracy and efficiency of g-RISB with dynamical mean-field theory (DMFT), weighing their respective advantages and disadvantages in simulating strongly correlated systems.