TY - JOUR
T1 - Phase stability and properties of manganese oxide polymorphs
T2 - Assessment and insights from diffusion Monte Carlo
AU - Schiller, Joshua A.
AU - Wagner, Lucas K.
AU - Ertekin, Elif
N1 - Funding Information:
J.A.S. acknowledges the support of a National Science Foundation Graduate Research Fellowship. E.E. and L.K.W. acknowledge the support of the National Center for Supercomputing Applications (NCSA) Faculty Fellows program. L.K.W was also supported by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, Scientific Discovery through Advanced Computing (SciDAC) program under Award No. FG02-12ER46875. This research is part of the Blue Waters sustained petascale computing project, which is supported by the National Science Foundation (Awards No. OCI 07-25070 and No. ACI-1238993) and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana–Champaign and its National Center for Supercomputing Applications. Also, this research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract No. DE-AC02-06CH11357. Computational resources were also provided by the Illinois Campus Computing cluster. We are very grateful to S. Lany for useful discussions.
PY - 2015/12/28
Y1 - 2015/12/28
N2 - We present an analysis of the polymorphic energy ordering and properties of the rocksalt and zinc-blende structures of manganese oxide using fixed node diffusion Monte Carlo (DMC). Manganese oxide is a correlated, antiferromagnetic material that has proven to be challenging to model from first principles across a variety of approaches. Unlike conventional density functional theory and some hybrid functionals, fixed node diffusion Monte Carlo finds the rocksalt structure to be more stable than the zinc-blende structure, and thus recovers the correct energy ordering. Analysis of the site-resolved charge fluctuations of the wave functions according to DMC and other electronic structure descriptions gives insights into elements that are missing in other theories. While the calculated band gaps within DMC are in agreement with predictions that the zinc-blende polymorph has a lower band gap, the gaps themselves overestimate reported experimental values.
AB - We present an analysis of the polymorphic energy ordering and properties of the rocksalt and zinc-blende structures of manganese oxide using fixed node diffusion Monte Carlo (DMC). Manganese oxide is a correlated, antiferromagnetic material that has proven to be challenging to model from first principles across a variety of approaches. Unlike conventional density functional theory and some hybrid functionals, fixed node diffusion Monte Carlo finds the rocksalt structure to be more stable than the zinc-blende structure, and thus recovers the correct energy ordering. Analysis of the site-resolved charge fluctuations of the wave functions according to DMC and other electronic structure descriptions gives insights into elements that are missing in other theories. While the calculated band gaps within DMC are in agreement with predictions that the zinc-blende polymorph has a lower band gap, the gaps themselves overestimate reported experimental values.
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U2 - 10.1103/PhysRevB.92.235209
DO - 10.1103/PhysRevB.92.235209
M3 - Article
AN - SCOPUS:84953375067
VL - 92
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 23
M1 - 235209
ER -