Application of the relativistic DV-X molecular orbital method to -uranium alloys with transition metals

Kurihara, Masayoshi*; Hirata, Masaru ; Onoe, Jun*; Nakamatsu, Hirohide*

The alloying behavior of 4d and 5d transition metals (TMs) in -phase solid uranium (U) has been investigated using the discrete-variational Dirac-Fock-Slater (DV-DFS) method. We examined the d-orbital energy (Md value) of these TMs, the orbital overlap population (OOP) between the d-orbital of these TMs and the 5f or 6d orbital of -U, and the effective charge on each atom of the -U/TM alloy, and the effect of these parameters on alloying. It was found that the maximum solid solubility of TMs into -U was exponentially proportional to both the Md and the OOP (U5f-TMd and U6d-TMd). We found a good correlation between the MSS and Md, the effective charge, or OOP.