Determination of the Mott insulating transition by the multi-reference density functional theory

It is shown that a momentum boost technique applied to the extended Kohn-Sham scheme enables the computational determination of the Mott insulating transition. Self-consistent solutions are given for correlated electron systems by first-principles calculations defined by the multi-reference density functional theory, in which the effective short-range interaction can be determined by the fluctuation reference method. An extension of the Harriman construction is made for the twisted boundary condition in order to define the momentum-boost technique in the first-principles manner. For an effectively half-filled-band system, the momentum-boost method tells that the period of a metallic ground state by the local density approximation (LDA) calculation is shortened to the least period of the insulating phase, indicating the occurrence of the Mott insulating transition.