  We present a method for electronic structure calculations that retains all of
the advantages of real space and addresses the inherent inefficiency of a
regular grid, which has equal precision everywhere. The computations are
carried out on a {\em regular} mesh in {\em curvilinear space}, which allows
natural and efficient decomposition on parallel computers, and effective use of
iterative numerical methods. A novel feature is the use of error analysis to
optimize the curvilinear grid for highly inhomogeneous electronic
distributions. We report accurate all-electron calculations for H$_2$, O, and
O$_{2}$.
