Improving efficiency of the continuous-time quantum Monte Carlo*

The dynamical mean field theory (DMFT) is a method to investigate strongly correlated materials. This method considers correlations effects in the solid through the Anderson impurity model (AIM). Because there is no analytic solution to AIM, we have to adopt numerical methods called impurity solver. Among various impurity solvers, we implemented continuous-time quantum Monte Carlo approach, which is numerically exact and allow us to deal with any two particle interaction hamiltonian. We tried to improve our impurity solver to calculate the self energy more efficiently and tested its accuracy by comparing it with several model studies. Moreover, we constructed DFT (density functional theory) + DMFT program by combining the developed solver with the SIESTA program. Then we calculated electronic structures of some materials and compared them with experimental data.