  With the aim of future applications in quantum mechanical embedding in
extended systems such as crystals, we suggest a simple and computationally
efficient method which enables construction of a set of nonorthogonal highly
localized one-electron orbitals for periodic nonmetallic crystals which reflect
their chemical nature. The orbitals are also used to build up the Hartree-Fock
(HF) electron density of the entire crystals. The simplicity of the method
stems from the fact that it does not require usage and/or modification of
periodic electronic structure codes, and is instead based on the HF calculation
of a sequence of finite clusters with subsequent application of a localization
procedure to transform the HF canonical molecular orbitals. Two extreme cases
of chemical bonding, ionic (MgO crystal) and covalent (Si crystal), are
considered for which a number of known localization schemes are applied and
compared. With some modifications our method can also be applied to nonperiodic
nonmetallic systems as well.
