Phase equilibria in the USi system from firstprinciples calculations
Density functional theory calculations have been used with spinorbit coupling and onsite Coulomb correction (GGA + U) methods to investigate the USi system. Structural prediction methods were employed to identify alternate stable structures. Convex hulls of the USi system were constructed for each of the methods to highlight the competing energetics of various phases. For GGA calculations, new structures are predicted to be dynamically stable, but these have not been experimentally observed. When the GGA + U (U _{eff} > 1.3 eV) method is considered, the experimentally observed structures are predicted to be energetically preferred. Phonon calculations were used to investigate the energy predictions and showed that the use of the GGA + U method removes the significant imaginary frequencies observed for U _{3}Si _{2} when the correction is not considered. In conclusion, total and partial electron density of states calculations were also performed to understand the role of GGA + U methods and orbitals on the bonding and stability of USi compounds.
 Authors:

^{[1]};
^{[1]};
^{[2]}
;
^{[3]};
^{[4]}
 Univ. of South Carolina, Columbia, SC (United States). Dept. of Mechanical Engineering, Nuclear Engineering Program
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Westinghouse Electric Sweden, Vasteras (Sweden)
 Missouri Univ. of Science and Technology, Rolla, MO (United States). Physics Dept.
 Publication Date:
 Report Number(s):
 LAUR1621445
Journal ID: ISSN 00223115
 Grant/Contract Number:
 AC5206NA25396
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Nuclear Materials
 Additional Journal Information:
 Journal Volume: 479; Journal Issue: C; Journal ID: ISSN 00223115
 Publisher:
 Elsevier
 Research Org:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org:
 USDOE National Nuclear Security Administration (NNSA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 36 MATERIALS SCIENCE
 OSTI Identifier:
 1458932
 Alternate Identifier(s):
 OSTI ID: 1359427
Noordhoek, Mark J., Besmann, Theodore M., Andersson, Anders David Ragnar, Middleburgh, Simon C., and Chernatynskiy, Aleksandr. Phase equilibria in the USi system from firstprinciples calculations. United States: N. p.,
Web. doi:10.1016/j.jnucmat.2016.07.006.
Noordhoek, Mark J., Besmann, Theodore M., Andersson, Anders David Ragnar, Middleburgh, Simon C., & Chernatynskiy, Aleksandr. Phase equilibria in the USi system from firstprinciples calculations. United States. doi:10.1016/j.jnucmat.2016.07.006.
Noordhoek, Mark J., Besmann, Theodore M., Andersson, Anders David Ragnar, Middleburgh, Simon C., and Chernatynskiy, Aleksandr. 2016.
"Phase equilibria in the USi system from firstprinciples calculations". United States.
doi:10.1016/j.jnucmat.2016.07.006. https://www.osti.gov/servlets/purl/1458932.
@article{osti_1458932,
title = {Phase equilibria in the USi system from firstprinciples calculations},
author = {Noordhoek, Mark J. and Besmann, Theodore M. and Andersson, Anders David Ragnar and Middleburgh, Simon C. and Chernatynskiy, Aleksandr},
abstractNote = {Density functional theory calculations have been used with spinorbit coupling and onsite Coulomb correction (GGA + U) methods to investigate the USi system. Structural prediction methods were employed to identify alternate stable structures. Convex hulls of the USi system were constructed for each of the methods to highlight the competing energetics of various phases. For GGA calculations, new structures are predicted to be dynamically stable, but these have not been experimentally observed. When the GGA + U (Ueff > 1.3 eV) method is considered, the experimentally observed structures are predicted to be energetically preferred. Phonon calculations were used to investigate the energy predictions and showed that the use of the GGA + U method removes the significant imaginary frequencies observed for U3Si2 when the correction is not considered. In conclusion, total and partial electron density of states calculations were also performed to understand the role of GGA + U methods and orbitals on the bonding and stability of USi compounds.},
doi = {10.1016/j.jnucmat.2016.07.006},
journal = {Journal of Nuclear Materials},
number = C,
volume = 479,
place = {United States},
year = {2016},
month = {7}
}