Poisson equation solver with fourth-order accuracy by using interpolated differential operator scheme,

A Poisson equation solver with fourth-order spatial accuracy has been developed by using the interpolated differential operator (IDO) scheme. The number of grids required for obtaining the results of numerical computation with the same accuracy as that by the second-order center finite difference method is drastically reduced. The consistency is confirmed to the use of the multigrid method and the red-black algorithm. The decrease of the CPU time by the multigrid method and by the parallel computing indicates the applicability of the IDO Poisson solver to large scale problems.