B. Winkler et al., A theoretical investigation of the relative stabilities of Fe-free clinozoisite and orthozoisite, PHYS CHEM M, 28(7), 2001, pp. 471-474
The relative stabilities of orthozoisite, Ca2Al3[O \ OH \ Si2O7\ SiO4], spa
ce group Pnma, and the monoclinic polymorph, clinozoisite, space group P2(1
)/m, have been investigated using calculations based on density functional
theory. It is found that orthozoisite is more stable than clinozoisite by a
bout 1 kJ mol(-1) at zero pressure in the athermal limit. The bulk moduli o
f the two polymorphs have been calculated to be B-ortho = 117.5(1.7) GPa an
d B-clino = 136(4) GPa.