<p>In
the present work, are calculated the gas formation enthalpies (SE; PM3 and PM6)
for tin borates: SnB<sub>2</sub>O<sub>4</sub><sup> </sup>and Sn<sub>2</sub>B<sub>2</sub>O<sub>5</sub>.
The calculated values are compared with experimental ones, obtained by Knudsen
effusion mass spectrometry [3]. It is
shown that SE methods, besides their lower computational time consuming can,
indeed, provide reliable gas phase formation enthalpy values for inorganic
compounds containing heavy metals.</p>