Short range hydrogen diffusion in Na3AlH6

被引：7

作者：

Monteferrante, Michele ^{[3
]}

Bonella, Sara ^{[1
,2
]}

Ciccotti, Giovanni ^{[1
,2
]}

机构：

[1] Univ Roma La Sapienza, Dipartimento Fis, Rome, Italy

[2] CNISM Unit 1, Rome, Italy

[3] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2011年 / 13卷 / 22期

基金：

爱尔兰科学基金会;

关键词：

FREE-ENERGY BARRIERS; REACTION COORDINATE; MOLECULAR-DYNAMICS; EFFICIENT;

D O I：

10.1039/c0cp02852e

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Ab initio free energy and rate calculations are performed to investigate two activated mobility processes observed, respectively, in neutron scattering and anelastic spectroscopy experiments on sodium alanates. The system is modeled as a Na3AlH6 crystal hosting one hydrogen vacancy. We identify the process observed via neutron scattering with a positively charged hydrogen vacancy diffusing from the AlH52- to one of the AlH63- groups. As for the anelastic spectroscopy experiments, our calculations negate the current hypothesis on the process, i.e. local rearrangement of the H vacancy around the pentacoordinated Al group.

引用

页码：10546 / 10555

页数：10

共 43 条

[1] Efficient and Direct Generation of Multidimensional Free Energy Surfaces via Adiabatic Dynamics without Coordinate Transformations [J].

Abrams, Jerry B. ;

Tuckerman, Mark E. .

JOURNAL OF PHYSICAL CHEMISTRY B, 2008, 112 (49) :15742-15757

[2]

[Anonymous], J ALLOYS COMPD

[3] Vacancy-mediated hydrogen desorption in NaAlH4 -: art. no. 165101 [J].

Araújo, CM ;

Li, S ;

Ahuja, R ;

Jena, P .

PHYSICAL REVIEW B, 2005, 72 (16)

[4] DENSITY-FUNCTIONAL EXCHANGE-ENERGY APPROXIMATION WITH CORRECT ASYMPTOTIC-BEHAVIOR [J].

BECKE, AD .

PHYSICAL REVIEW A, 1988, 38 (06) :3098-3100

[5] Transition path sampling: Throwing ropes over rough mountain passes, in the dark [J].

Bolhuis, PG ;

Chandler, D ;

Dellago, C ;

Geissler, PL .

ANNUAL REVIEW OF PHYSICAL CHEMISTRY, 2002, 53 :291-318

[6] CONSTRAINED REACTION COORDINATE DYNAMICS FOR THE SIMULATION OF RARE EVENTS [J].

CARTER, EA ;

CICCOTTI, G ;

HYNES, JT ;

KAPRAL, R .

CHEMICAL PHYSICS LETTERS, 1989, 156 (05) :472-477

[7]

*CPMD, 1999, COP MPI FESTK STUTTG

[8] Transition-Path Theory and Path-Finding Algorithms for the Study of Rare Events [J].

E, Weinan ;

Vanden-Eijnden, Eric .

ANNUAL REVIEW OF PHYSICAL CHEMISTRY, VOL 61, 2010, 61 :391-420

[9] Hydrogen diffusion in MgH2 and NaMgH3 via concerted motions of charged defects [J].

Hao, Shiqiang ;

Sholl, David S. .

APPLIED PHYSICS LETTERS, 2008, 93 (25)

[10] A climbing image nudged elastic band method for finding saddle points and minimum energy paths [J].

Henkelman, G ;

Uberuaga, BP ;

Jónsson, H .

JOURNAL OF CHEMICAL PHYSICS, 2000, 113 (22) :9901-9904

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