Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2011, Vol. 22 ›› Issue (1): 47-54 doi: 10.13538/j.1001-8042/nst.22.47-54

• NUCLEAR, HEAVY ION AND ATOMIC PHYSICS • Previous Articles     Next Articles

Structures and potential energy functions for ground states of PuU and U2 molecules

LI Rusong* HE Bin ZHANG Quanhu   

  1. Xi’an Research Institute of Hi-Tech, Hongqing Town, Xi’an 710025, China
LI Rusong, HE Bin, ZHANG Quanhu. Structures and potential energy functions for ground states of PuU and U2 molecules.Nuclear Science and Techniques, 2011, 22(1): 47-54     doi: 10.13538/j.1001-8042/nst.22.47-54

Abstract:

Pu-Pu, Pu-U and U-U interatomic potentials must be known in molecular dynamics (MD) calculation of the effects of U recoil nucleus produced by self irradiation on physical properties and phase stability in δ-Pu. Because of the lack of experimental data for fitting Pu-U and U-U potentials, electronic states and potential data of PuU and U2 molecules are obtained by ab initio calculations with B3LYP hybrid exchange-correlation functional. The valence electrons of Pu and U atoms are treated with contraction basis sets, and the cores are approximated with relativistic effective core potential. The results show that electronic states for the ground states are X11Σu + and X9Σg +. The pair potential data are fitted with the Murrell-Sorbie analytical potential function. The LDA+U calculations on the Pu-U intermetallic compound are performed with Perdew and Wang exchange-correlation functional at the spin-polarized level. The material parameters, such as the cohesive energies, elastic constants, and bulk modulus, are used to fit the 0-K universal Rose EOS, so the Pu-U EAM potential model is obtained.

Key words: Ab initio, Electronic state, Dissociation energy, Potential