Diffusion Monte Carlo Calculations for Rare-earths: Applying the Long-range Corrected Scheme to Minnesota M06 Functional

By employing the diffusion Monte Carlo (DMC) method, we test the success of the unpublished long-range corrected M06 (LC-M06) functional, compared to LC-BLYP functional, in improving the calculations of the ground and excited states energies for some 4f- and 5f-rare-earths at different values of the range separation parameter μ. It is found that LC-M06 functional performs well for both the ground and the excited states of 4f-lanthanides. In addition, our results reveal that the optimal value of μ for the ground state lies between 0.40-0.50 a.u. while a smaller optimal value μ =0.35 a.u. is found for the excited states. However, LC-BLYP ground and excited states results at the optimal value of μ seem to be the best for 5f-actinides.