  We have developed an efficient computational scheme utilizing the real-space
finite-difference formalism and the projector augmented-wave (PAW) method to
perform precise first-principles electronic-structure simulations based on the
density functional theory for systems containing transition metals with a
modest computational effort. By combining the advantages of the time-saving
double-grid technique and the Fourier filtering procedure for the projectors of
pseudopotentials, we can overcome the egg box effect in the computations even
for first-row elements and transition metals, which is a problem of the
real-space finite-difference formalism. In order to demonstrate the potential
power in terms of precision and applicability of the present scheme, we have
carried out simulations to examine several bulk properties and structural
energy differences between different bulk phases of transition metals, and have
obtained excellent agreement with the results of other precise first-principles
methods such as a plane wave based PAW method and an all-electron
full-potential linearized augmented plane wave (FLAPW) method.
