We discuss our experiments and coordinated computational modeling that show the value of magnetic moment measurements for helping to identify the site selection of an additive to an intermetallic compound. Magnetic susceptibility measurements (5K-300K) were used to determine additive (V, Cr, Mn) moments; and the site distribution was determined experimentally by measuring the relative variations of the (001) and (110) x-ray diffraction superlattice lines and comparing to the expected behavior for occupation of either site, or a distribution between sites. This gives us a predicted relationship of measured additive moment to site distribution which was then further validated by comparison to our ab initio calculation of the moments for Ti site occupation (as expected at low additive concentrations from total energy considerations). The moments (calculated using the cluster discrete variational (LCAO) method with isolated impurities) of 1.21, 2.36 and 2.52 μB for V, Cr and Mn, respectively compare favorably to the lowest-concentration experimental values of 1.01 and 2.3 μB for V and Mn, respectively; while the disagreement for Cr with low-concentration experimental moment of 0.55 μB may be due to additive clustering effects not included in the single-additive-atom cluster calculations or to multivalent behavior of Cr. The experimental decrease of V and Cr moment with concentration indicates a shift from Ti site occupancy toward increasing Al site occupancy with increase in V and Cr concentration.