A partitioning scheme based on the use of density and overlap matrixes of allocating
the electrons of a molecular entity in some fractional manner among its various parts
(atoms, bonds, orbitals). As with other schemes of partitioning the
electron density in molecules,
MPA is arbitrary and strongly dependent on the particular
basis set employed. However, comparison of population analyses for a series of molecules is
useful for a quantitative description of intra-molecular interactions, chemical reactivity
and structural regularities.
Source: