Analysis of the melting temperatures of RT2 compounds (MgCu2 structure) (R=Rare Earth, TMn, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) and RT2X2 compounds (RLa, Ce, Sm, Er; TMn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Pt; XSi, Ge)

Physico-chemical analysis techniques, including X-ray phase analysis and differential thermal analysis were employed for the characterisation of compounds including their melting temperature. The melting temperature for 70 RT2X2 compounds has been measured (R=(La, Ce, Sm, Er, Tm), T=(Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Pt), X=(Si, Ge)). It is established, that the compounds CePt2Ge2, LaPt2Si2, LaPt2Ge2 belong to the CaBe2Ge2 structure type (group P4/mmm): LaPt2Si2 (a=0.4280(2) nm, c=0.9831(6) nm); LaPt2Ge2 (a=0.4417(3) nm, c=0.976(2) nm) and CePt2Ge2 (a=0.44033(4) nm, c=0.9808(1)). An empirical model able to describe the melting temperature of Tm of the compounds RT2, RT2X2 with accuracy often better than 5% is presented: Tm = const/V13, where the constant factor depends on the type of atoms constituting the compound, and where V is unit cell volume.