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This content will become publicly available on July 21, 2018

Title: Complexity Reduction in Large Quantum Systems: Fragment Identification and Population Analysis via a Local Optimized Minimal Basis

We present, within Kohn-Sham Density Functional Theory calculations, a quantitative method to identify and assess the partitioning of a large quantum mechanical system into fragments. We then introduce a simple and efficient formalism (which can be written as generalization of other well-known population analyses) to extract, from first principles, electrostatic multipoles for these fragments. The corresponding fragment multipoles can in this way be seen as reliable (pseudo-) observables. By applying our formalism within the code BigDFT, we show that the usage of a minimal set of in-situ optimized basis functions is of utmost importance for having at the same time a proper fragment definition and an accurate description of the electronic structure. With this approach it becomes possible to simplify the modeling of environmental fragments by a set of multipoles, without notable loss of precision in the description of the active quantum mechanical region. Furthermore, this leads to a considerable reduction of the degrees of freedom by an effective coarsegraining approach, eventually also paving the way towards efficient QM/QM and QM/MM methods coupling together different levels of accuracy.
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [4]
  1. Barcelona Supercomputing Center (BSC), Barcelona (Spain)
  2. Institut de Biologie et de Technologie de Saclay, Gif-sur-Yvette Cedex (France)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Univ. Grenoble Alpes, Grenoble (France); CEA, Grenoble (France)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Theory and Computation
Additional Journal Information:
Journal Volume: 13; Journal Issue: 9; Journal ID: ISSN 1549-9618
Publisher:
American Chemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
European Commission, Community Research and Development Information Service (CORDIS), EXTended Model of Organic Semiconductors (ExtMOS); Energy Oriented Centre of Excellence (EoCoE); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Argonne National Laboratory, Argonne Leadership Computing Facility; MaX Centre of Excellence
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1400406