The structures and physical properties of diopside, walstromite, wollastonite, parawollastonite, pseudowollastonite, wollastonite-II, and CaSiO3 perovskite were simulated by computational models using energy minimization technique. The potential energies of these crystals are approximated by the sum of Coulomb, van der Waals, and repulsion terms between atoms. Required potential energy parameters of Ca and Ba were determined by fitting the calculated crystal structures of diopside and walstromite, and calculated bulk modulus of diopside to the observed ones. Using the obtained potential parameters of Ca and Ba, together with those of Mg, Si, and O derived from Matsui (1988), crystal structures of wollastonite, parawollastonite, pseudowollastonite, wollastonite-II, and CaSiO3 perovskite were reproduced well. The elastic constants of diopside and the bulk modulus of CaSiO3 perovskite were also simulated, and the values are in agreement with experimental data. These potential parameters were applied to predicting the bulk moduli and linear compressibilities of interatomic bonds of these crystals. The results of these calculations show that bulk modulus and compressibilities of M(Mg,Ca,Ba)-O bonds are related with crystal structures.