Table 1.

Lattice energy calculations (E_latt) of 0.33-Hy, 01_1963, forms II and III and the isomorphic dehydrate structure (0.33-Hy without water molecules, Hy_dehy) and potential energy differences (Δ_trsU) with respect to form III.

Form	Elatt/kJ mol−1	ΔtrsUx−III/kJ mol−1
0.33-Hy	−222.95	15.37a
Hydehy	−197.26	−0.90b
01_1963	−269.54	12.38a
Form II	−194.92	−3.25b
Form III	−198.16	0b

^aCalculated according to: –Δ_trsU_x−III = E_latt-x – (E_latt-III + E_latt-ICE).

^b–Δ_trsU_x−III = E_latt-x– E_latt-III.