Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Thermodynamic properties of metaschoepite predicted from density functional perturbation theory

Journal Article · · Chemical Physics Letters

Density functional perturbation theory (DFPT) calculations of the thermodynamic properties of metaschoepite, (UO2)802(OH)12•10H20, are reported. Using a recently revised crystal structure of metaschoepite, the predicted molar entropy and isobaric heat capacity are overall significantly smaller than previous calculations using an earlier orthorhombic crystal structure model. The present DFPT calculations also show large differences between the thermo-dynamic functions of metaschoepite and schoepite, which might reflect the change in phonon properties upon removal of two H20 molecules per formula unit and alteration of the H-bonded interlayer water network from schoepite to metaschoepite.

Research Organization:
Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5)
Grant/Contract Number:
AC04-94AL85000
OSTI ID:
1670745
Alternate ID(s):
OSTI ID: 1775637
Report Number(s):
SAND2020--7387J; 687474
Journal Information:
Chemical Physics Letters, Journal Name: Chemical Physics Letters Vol. 757; ISSN 0009-2614
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (20)

Thermochemical Data of Pure Substances book October 1995
Matrix Eigenvector Methods book January 1983
On the uranates of ammonium—II journal August 1963
Prediction of mechanical properties of grafted kaolinite – A DFT study journal August 2020
Periodic Density Functional Theory Study of the Structure, Raman Spectrum, and Mechanical Properties of Schoepite Mineral journal March 2018
Elucidation of the Structure and Vibrational Spectroscopy of Synthetic Metaschoepite and Its Dehydration Product journal May 2019
Uncloaking the Thermodynamics of the Studtite to Metastudtite Shear-Induced Transformation journal July 2016
Periodic DFT Study of the Thermodynamic Properties and Stability of Schoepite and Metaschoepite Mineral Phases journal December 2018
Layered uranium( vi ) hydroxides: structural and thermodynamic properties of dehydrated schoepite α-UO 2 (OH) 2 journal January 2014
Structure–thermodynamics relationship of schoepite from first-principles journal January 2019
Ab initio study of the uranyl oxide hydrates: a proton transfer mediated by water journal May 2007
Projector augmented-wave method journal December 1994
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set journal October 1996
Ab initio study of uranyl peroxides: Electronic factors behind the phase stability journal February 2007
First-principles calculations of the ferroelastic transition between rutile-type and CaCl 2 -type SiO 2 at high pressures journal October 2008
Generalized Gradient Approximation Made Simple journal October 1996
Structure of uranium(VI) oxide dihydrate, UO 3 ·2H 2 O; synthetic meta -schoepite (UO 2 ) 4 O(OH) 6 ·5H 2 O journal August 2000
Thermochemistry of uranium compounds. XVI. Calorimetric determination of the standard molar enthalpy of formation at 298.15 K, low-temperature heat capacity, and high-temperature enthalpy increments of UO 2 (OH 2 )•H 2 O (schoepite) journal April 1988
Neptunium incorporation in sodium-substituted metaschoepite journal April 2007
Paulscherrerite from the Number 2 Workings, Mount Painter Inlier, Northern Flinders Ranges, South Australia: "Dehydrated schoepite" is a mineral after all journal February 2011

Similar Records

Structure–thermodynamics relationship of schoepite from first-principles
Journal Article · Tue Sep 24 00:00:00 EDT 2019 · Physical Chemistry Chemical Physics. PCCP · OSTI ID:1574710

Schoepite and dehydrated schoepite
Conference · Thu Aug 01 00:00:00 EDT 1996 · OSTI ID:264441

Formation of a uranyl hydroxide hydrate via hydration of [(UO2F22O)]7·4H2O
Journal Article · Fri Aug 30 00:00:00 EDT 2019 · Dalton Transactions · OSTI ID:1607115