Grand canonical electronic density-functional theory: Algorithms and applications to electrochemistry
First-principles calculations combining density-functional theory and continuum solvation models enable realistic theoretical modeling and design of electrochemical systems. When a reaction proceeds in such systems, the number of electrons in the portion of the system treated quantum mechanically changes continuously, with a balancing charge appearing in the continuum electrolyte. A grand-canonical ensemble of electrons at a chemical potential set by the electrode potential is therefore the ideal description of such systems that directly mimics the experimental condition. We present two distinct algorithms: a self-consistent field method and a direct variational free energy minimization method using auxiliary Hamiltonians (GC-AuxH), to solve the Kohn-Sham equations of electronic density-functional theory directly in the grand canonical ensemble at fixed potential. Both methods substantially improve performance compared to a sequence of conventional fixed-number calculations targeting the desired potential, with the GC-AuxH method additionally exhibiting reliable and smooth exponential convergence of the grand free energy. Lastly, we apply grand-canonical density-functional theory to the under-potential deposition of copper on platinum from chloride-containing electrolytes and show that chloride desorption, not partial copper monolayer formation, is responsible for the second voltammetric peak.
- Authors:
-
[1]
; [2]
; [3]
- Rensselaer Polytechnic Inst., Troy, NY (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States)
- California Inst. of Technology (CalTech), Pasadena, CA (United States)
- Cornell Univ., Ithaca, NY (United States)
- Publication Date:
- Grant/Contract Number:
- SC0004993; SC0001086; AC02-05CH11231
- Type:
- Accepted Manuscript
- Journal Name:
- Journal of Chemical Physics
- Additional Journal Information:
- Journal Volume: 146; Journal Issue: 11; Journal ID: ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)
- Research Org:
- California Institute of Technology, Pasadena, CA (United States)
- Sponsoring Org:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Science (SC)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 97 MATHEMATICS AND COMPUTING
- OSTI Identifier:
- 1347429
- Alternate Identifier(s):
- OSTI ID: 1348036
- Free Publicly Accessible Full Text
- Accepted Manuscript (Publisher)
-
Accepted Manuscript (DOE)
- Publisher's Version of Record
- https://doi.org/10.1063/1.4978411