The database knows only 6 reports of MCd3 phase in Cu3Au-type structure. One report got into the database by mistake, given that the phase ZrCd2 was reported as the one adopting the Cu3Au-type structure. One could assume that it was just a Cd-site defective variant of ZrCd3, however, in the original publication, the authors list systematic absences originating from a-and n-glide planes within the cubic system, which obviously are not present in the Pm3m space group of the Cu3Au-type structure. One more phase reported has a composition of Pt3Cd resulting in a structure with the opposite M/Cd site assignment compared to what we got. Another reciprocal atomic arrangement was observed in La3In0.9Cd0.1. A similar to our atomic assignment reported phases are NbCd3 and a series of REIn3-xCdx phases, which feature Cd only as a minor substitution in the In site. With this information, from a chemical intuition point of view, the formation of UCd3 would not seem to be obvious. Looking at the formation trends of U-containing compounds (Figure ), binary phases adopting Cu3Autype were only limited to group 13 and 14 elements, and some Fe-family members (dark blue). Even extending the potential phase search, to ternary solid solution variations of Cu3Au-type (light blue), Cd did not seem to be an obvious choice for an exploratory synthesis, given that it never before formed an ordered intermetallic compound with uranium. Exploration of the existence of UCd3 with conventional systematic study would be associated with radioactive element risk (U) and toxic risk (Cd) therefore would not be favored by experimentalists from a safety perspective. In our case, machine learning prediction was a significant factor to explore the U-Cd system for UCd3 phase existence, given that the probability of UCd3 compound adopting a Cu3Au-type structure was the fourth highest among all test composition predictions (Figure ). To confirm ML predictions that UCd3 should exist and its structure type should be Cu3Au, we synthesized the compound. Handling uranium and cadmium, elements that require extra caution, was not the only challenge. Cadmium is an element that has a high vapor pressure, melts and sublimes easily at relatively low temperatures. Additionally, the most common reaction temperatures for Cu3Au-type intermetallics are 600, 800, and 1000 ℃, which correspond to the phase transitions of uranium metal (Figure ). The phase transitions occur at 668 °C (α-U to β-U), 776 °C (β -U to γ-U), and 1120 °C (γ-U to liquid). This provides us with four different reactants at the convenient range of temperatures to explore how structure of the reactant influences the formation of a solid-state phase, rather than solely focusing on the composition of the reactants. The selected system is challenging for synthetic chemists because of: (1) radioactive element uranium, (2) toxic element cadmium, (3) volatility of cadmium, (4) proximity to the phase transition of the reactant, (5) uranium tendency to oxidize. Even in the event when the UCd3 compound indeed forms, one can expect a shift from the original sample composition (losing Cd), nonequilibrium sample (presence of uranium oxide phase), additional violation of the phase rule due to suppressed transformation of the structure of uranium metal. Two samples were prepared to test the formation of UCd3. Stoichiometric mixture of freshly filed uranium metal (Luciteria, 99.99%) and cadmium metal (Alfa, 99.99%), with a total mass of 0.3g, were pressed into a pellet and sealed in tantalum crucible in an evacuated fused silica tube. The first sample was slowly heated to 750 ℃ and kept at this temperature for one week. The second sample was slowly heated to 400 ℃, then slowly heated to 900 ℃, then slowly cooled to 850 ℃, then slowly cooled to 750 ℃, kept at this temperature for a week, and quenched in cold water. On the walls of both tubes some newly crystallized cadmium metal was found, while the pellets were visually homogeneous. The first sample was ground in an agate mortar and analyzed with X-ray powder diffraction method (Bruker Phaser D2, CuKα). The diffraction pattern was refined with the Pawley fit method in Topas Academic software package for the first sample (Figure ) and the second sample (Figure ). The fit of the first sample was matching well with the content of unreacted uranium (that underwent phase transition to β-U), uranium oxide, and unreacted cadmium. This agrees well with our expectations regarding nonhomogeneity of the sample. No traces of γ-U adopting high symmetry were found on the powder pattern. The fit of the second sample had the same phases and additional peaks (detailed data comparison and relative intensity of the peaks on Figure ) that agree with UCd3 phase in Pm3m space group with cell parameter a = 4.648(2) Å, in Cu3Au-type structure, as it was predicted by our machine learning model. The difference in the powder patterns and formation of UCd3 phase is mainly attributed to the formation of γ-U at 900 ℃, which epitactically grows UCd3 phase. The presence of unreacted γ-U was not confirmed. This way we experimentally validated the predicted structure type of UCd3 phase, based on the features that were generated with the Oliynyk property list. We are confident that the proposed in-lab property list can lead to many ML-guided discoveries in the future.