Hence, in spite of EuCdPt being reported in the TiNiSi type, the one remarkable feature of the intergrowth title phase is that the TiNiSi related slabs are occupied by rather Mn while the Cd are located in the ZrNiAl related slabs. This is counter-intuitive, particularly because "EuMnPt" have remained elusive and, excess amount of Cd was used in the starting mixture resulting in larger amount of 22 % Cd at the Mn mainly occupied positions, twice the value of 11 % Mn at Cd mainly occupied sites. While the isovalent Cd and Mn atoms could randomly mix in both CeCdxMn1-xPt (hexagonal ZrNiAl type) and YbCdxMn1-xPt (orthorhombic TiNiSi type) rival structures, the strong site preferences in the Eu analogue are somewhat unexpected in part because both Cd and Mn are in tetrahedral coordination of four Pt atoms. Thus, the site preference may be ascribed to rather the system tendency to favour homonuclear Mn-Mn contacts, over heteronuclear Cd-Mn, and the least favourable homonuclear Cd-Cd contacts in that order, as dictated by the 18-n rule. The larger atomic size of divalent Eu as compared to trivalent Ce and divalent Yb may also be critical to stabilize the intergrowth LaNiAl type over simple TiNiSi and ZrNiAl parent structures. The LaNiAl type can offer tetrahedral coordination geometry for the both isovalent Mn and Cd atoms as in the TiNiSi type, while the two Pt occupied sites have markedly different coordination environment. Ultimately, the Eu sublattice is more typical of the ZrNiAl type which is known to achieve more efficient packing than the TiNiSi type. Since the TiNiSi type is known to be reluctant to heteroatomic localized (Zinc blend like) covalent bonding, the very similar atomic size between Mn and Pt may also play a role. However, EuxYb1-xMnPt is stabilized in the TiNiSi type with MnPt4 tetrahedra that are only slightly distorted. The investigations of the electronic structure and bonding picture of the title phase with the help of quantum mechanical calculations are warranted in order to understand the similarities and differences between Cd-Pt and Mn-Pt bond in particular, which is crucial to explain the site preferences.