  A non-iterative method is presented to calculate the closest Wannier
functions (CWFs) to a given set of localized guiding functions, such as atomic
orbitals, hybrid atomic orbitals, and molecular orbitals, based on minimization
of a distance measure function. It is shown that the minimization is directly
achieved by a polar decomposition of a projection matrix via singular value
decomposition, making iterative calculations and complications arising from the
choice of the gauge irrelevant. The disentanglement of bands is inherently
addressed by introducing a smoothly varying window function and a greater
number of Bloch functions, even for isolated bands. In addition to atomic and
hybrid atomic orbitals, we introduce embedded molecular orbitals in molecules
and bulks as the guiding functions, and demonstrate that the Wannier
interpolated bands accurately reproduce the targeted conventional bands of a
wide variety of systems including Si, Cu, the TTF-TCNQ molecular crystal, and a
topological insulator of Bi$_2$Se$_3$. We further show the usefulness of the
proposed method in calculating effective atomic charges. These numerical
results not only establish our proposed method as an efficient alternative for
calculating WFs, but also suggest that the concept of CWFs can serve as a
foundation for developing novel methods to analyze electronic structures and
calculate physical properties.
