Abstract: | A procedure for the calculation of molar volumes of solids in their polymorphic transformations with increased coordination number is described. Assuming that these transformations occur under high pressures we have calculated the pressures responsible for volume changes using the Murnaghan equation. The same values were estimated based on the principle of equalized intermolecular distances in polymorphic transformations, in satisfactory agreement with the first method. To realize the second procedure, we have obtained volume values of van der Waals radii for the elements of Subgroups 5 to 7b of the Periodic Table.Center of Dynamic High Pressures. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 4, pp. 112–116, July–August, 1993.Translated by T. Yudanova |