Crystal structure of the R2Ni22C3 compounds (R=Ce, La, Pr)

The results of determination of the Ce2Ni22C3 (space group, Csub(mca), a=1.1384 (3), b=1.5024 (7), c=1.4671 (5) nm, V=2.5092 nm3, Z=8, N=216) compound crystal structure are presented. Monocrystal is surveyed in the automatic diffractometer ''Sintex P21'' (890 reflections, MOK-radiation, theta/20-method, graphite monochromator, 2thetasub(max)=110 deg). The atomic coordinates atoms are defined in an isotropic approximation up to R=0.082. The lattice cell parameters of the La2Ni22C3 and Pr2Ni22C3 isostructural compounds are refined, using the least square method, from diffraction diagrams, obtained using DRON-2.0 (FeKsub(α)-radiation) and are equal to a=1.145 (5), b=1.512 (4), c=1.463 (4) nm; a=1.138 (4), b=1.505 (3), c=1.459 (3) nm, respectively. Interatomic distances for Ce2Ni22C3 are presented