Center for Molecular Modeling - G. Van Oost

Dislocation mechanism of deuterium retention in tungsten under plasma implantation

alex — Tue, 19 Aug 2014 11:54:30 +0000

V. Dubinko, D. Terentyev, P. Grigorev, A. Bakaev, G. Van Oost, F. Gao, D. Van Neck, E. Zhurkin

Journal of Physics: Condensed Matter

26, 395001

2014

Abstract

We have developed a new theoretical model for deuterium (D) retention in tungsten-based alloys on the basis of its being trapped at dislocations and transported to the surface via the dislocation network with parameters determined by ab initio calculations. The model is used to explain experimentally observed trends of D retention under sub-threshold implantation, which does not produce stable lattice defects to act as traps for D in conventional models. Saturation of D retention with implantation dose and effects due to alloying of tungsten with, e.g. tantalum, are evaluated, and comparison of the model predictions with experimental observations under high-flux plasma implantation conditions is presented.

DOI

http://dx.doi.org/10.1088/0953-8984/26/39/395001

Private attachment

14_JPhysCondensMatter_26,395001_Dubinko.pdf

Error estimates for solid-state density-functional theory predictions: an overview by means of the ground-state elemental crystals

kurt — Thu, 31 Jan 2013 07:34:07 +0000

K. Lejaeghere, V. Van Speybroeck, G. Van Oost, S. Cottenier

Critical Reviews in Solid State and Materials Sciences

39 (1), 1-24

2014

Abstract

Predictions of observable properties by density-functional theory calculations (DFT) are used increasingly often by experimental condensed-matter physicists and materials engineers as data. These predictions are used to analyze recent measurements, or to plan future experiments in a rational way. Increasingly more experimental scientists in these fields therefore face the natural question: what is the expected error for such a first-principles prediction? Information and experience about this question is implicitly available in the computational community, scattered over two decades of literature. The present review aims to summarize and quantify this implicit knowledge. This eventually leads to a practical protocol that allows any scientist -- experimental or theoretical -- to determine justifiable error estimates for many basic property predictions, without having to perform additional DFT calculations.

A central role is played by a large and diverse test set of crystalline solids, containing all ground-state elemental crystals (except most lanthanides). For several properties of each crystal, the difference between DFT results and experimental values is assessed. We discuss trends in these deviations and review explanations suggested in the literature.

A prerequisite for such an error analysis is that different implementations of the same first-principles formalism provide the same predictions. Therefore, the reproducibility of predictions across several mainstream methods and codes is discussed too. A quality factor Delta expresses the spread in predictions from two distinct DFT implementations by a single number. To compare the PAW method to the highly accurate APW+lo approach, a code assessment of VASP and GPAW (PAW) with respect to WIEN2k (APW+lo) yields Delta-values of 1.8 and 3.3 meV/atom, respectively. In both cases the PAW potentials recommended by the respective codes have been used. These differences are an order of magnitude smaller than the typical difference with experiment, and therefore predictions by APW+lo and PAW are for practical purposes identical.

DOI

http://dx.doi.org/10.1080/10408436.2013.772503

Private attachment

Lejaeghere_2014_CritRevSolidState_error-bars-DFT.pdf

Ab initio modeling of fusion reactor materials: Unravelling the hydrogen retention mechanisms

alex — Tue, 19 Aug 2014 12:27:38 +0000

A. Bakaev, P. Grigorev, V. Dubinko, D. Terentyev, W. Van Renterghem, G. Van Oost

ISBN/ISSN:

Poster

Conference / event / venue

International Conference on Scientific Computing 2013

Paphos, Cyprus

Tuesday, 3 December, 2013 to Friday, 6 December, 2013

Trapping of H on dislocations and grain boundaries in W alloys: an atomistic study

alex — Tue, 19 Aug 2014 12:22:32 +0000

A. Bakaev, P. Grigorev, V. Dubinko, D. Terentyev, W. Van Renterghem, G. Van Oost

ISBN/ISSN:

Poster

Conference / event / venue

14th International Conference on Plasma-Facing Materials and Components for Fusion Applications

Julich, Germany

Monday, 13 May, 2013 to Friday, 17 May, 2013

The ground state elemental crystals as a guideline for the assessment of solid state DFT accuracy

kurt — Tue, 14 Jan 2014 14:11:29 +0000

K. Lejaeghere, V. Van Speybroeck, G. Van Oost, S. Cottenier

ISBN/ISSN:

Poster

Conference / event / venue

(presenting author: K. Lejaeghere), BPS 2012

Brussels, Belgium

Wednesday, 30 May, 2012

Abstract (private)

abstract_BPS.pdf

The ground state elemental crystals as a guideline for the assessment of solid state DFT accuracy

kurt — Mon, 15 Jul 2013 06:13:34 +0000

K. Lejaeghere, V. Van Speybroeck, G. Van Oost, S. Cottenier

ISBN/ISSN:

Invited talk

Conference / event / venue

(presenting author K. Lejaeghere), NIST Workshop on Atomistic Simulations for Industrial Needs

Gaithersburg, MD, USA

Tuesday, 13 August, 2013 to Wednesday, 14 August, 2013

Abstract (private)

abstractCECAM.pdf

Conference reference

Workshops on Atomistic Simulations for Industrial Needs

O. Van Hoey

wim — Wed, 24 Apr 2013 10:28:41 +0000

Project promotor

G. Van Oost, V. Van Speybroeck

Financierende instantie

FWO-aspirant

Project data

01/10/2010 to 30/09/2014

Mandaatmaanden

48 months

Project titel

Material research for nuclear fusion

Personeel

O. Van Hoey

Plastic deformation of Fe-Ni-Cr alloys under irradiation: atomic-level study

alex — Wed, 17 Apr 2013 15:21:12 +0000

A. Bakaev, D. Van Neck, G. Van Oost, D. Terentyev

ISBN/ISSN:

Poster

Conference / event / venue

Day of the PhD's 2011, SCK-CEN

Mol, Belgium

Thursday, 6 October, 2011

The ground state elemental crystals as a benchmark for solid state DFT: intrinsic accuracy and code comparison

stefaan — Tue, 12 Feb 2013 07:47:46 +0000

K. Lejaeghere, G. Van Oost, V. Van Speybroeck, S. Cottenier

p. 59

Talk

Conference / event / venue

(presenting author S. Cottenier) Ab initio Description of Iron and Steel: Thermodynamics and Kinetics (ADIS 2012)

Ringberg Castle (Tegernsee, Germany)

Sunday, 29 April, 2012 to Friday, 4 May, 2012

Abstract (private)

ADIS2012-Abstract-Cottenier-Talk.pdf

Conference reference

ADIS 2012

Error bars for solid-state density-functional theory predictions

wim — Thu, 06 Sep 2012 12:23:07 +0000

K. Lejaeghere, G. Van Oost, V. Van Speybroeck, S. Cottenier

Invited talk

Conference / event / venue

(presenting author S. Cottenier), 17th ETSF Workshop on Electronic Excitations

Coimbra, Portugal

Monday, 1 October, 2012 to Friday, 5 October, 2012

Conference reference

17th ETSF Workshop on Electronic Excitations