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Title: Accurate thermoelastic tensor and acoustic velocities of NaCl

Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.
Authors:
 [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [4] ;  [2]
  1. Physics Institute, University of Sao Paulo, Sao Paulo, 05508-090 (Brazil)
  2. (United States)
  3. School of Physics and Astronomy, University of Minnesota, Minneapolis, 55455 (United States)
  4. Chemical Engineering and Material Science, University of Minnesota, Minneapolis, 55455 (United States)
Publication Date:
OSTI Identifier:
22492247
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 12; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ELASTICITY; ELECTRON CORRELATION; EQUATIONS OF STATE; MINERALS; OILS; PRESSURE MEASUREMENT; SALT DEPOSITS; SODIUM CHLORIDES; SOLIDS; SYMMETRY; TEMPERATURE MEASUREMENT; TENSORS; THERMODYNAMICS; VELOCITY