This structure has not been experimentally confirmed, but it has frequently been predicted as a low energy structure. (Hart, 2009) has a review of these calculations. It was originally given the $L1_{3}$ designation. As this has been frequently used in the literature ( e.g. Mehl, 2017), we will continue to used it despite the possible confusion.
Data for this structure comes from the supplemental material of (Hart, 2013).
G. L. W. Hart, Verifying predictions of the L1$_3$ crystal structure in Cd-Pt and Pd-Pt by exhaustive enumeration, Phys. Rev. B 80, 014106 (2009), doi:10.1103/PhysRevB.80.014106.
G. L. W. Hart, S. Curtarolo, T. B. Massalski, and O. Levy, Comprehensive Search for New Phases and Compounds in Binary Alloy Systems Based on Platinum-Group Metals, Using a Computational First-Principles Approach, Phys. Rev. X 3, 041305 (2013), doi:10.1103/PhysRevX.3.041035.
P. P. Ewald and C. Hermann, eds., Strukturbericht 1913-1928 (Akademische Verlagsgesellschaft M. B. H., Leipzig, 1931).
M. J. Mehl, D. Hicks, C. Toher, O. Levy, R. M. Hanson, G. Hart, and S. Curtarolo, The AFLOW library of crystallographic prototypes: part 1, Comp. Mater. Sci. 136, S1–S828 (2017), doi:10.1016/j.commatsci.2017.01.017.
First cited in
M. J. Mehl, D. Hicks, C. Toher, O. Levy, R. M. Hanson, G. L. W. Hart, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 1, Comp. Mat. Sci. 136, S1-S828 (2017). (doi=10.1016/j.commatsci.2017.01.017)