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This content will become publicly available on December 12, 2018

Title: Parametrization and Benchmark of Long-Range Corrected DFTB2 for Organic Molecules

In this paper, we present the parametrization and benchmark of long-range corrected second-order density functional tight binding (DFTB), LC-DFTB2, for organic and biological molecules. The LC-DFTB2 model not only improves fundamental orbital energy gaps but also ameliorates the DFT self-interaction error and overpolarization problem, and further improves charge-transfer excited states significantly. Electronic parameters for the construction of the DFTB2 Hamiltonian as well as repulsive potentials were optimized for molecules containing C, H, N, and O chemical elements. We use a semiautomatic parametrization scheme based on a genetic algorithm. With the new parameters, LC-DFTB2 describes geometries and vibrational frequencies of organic molecules similarly well as third-order DFTB3/3OB, the de facto standard parametrization based on a GGA functional. Finally, LC-DFTB2 performs well also for atomization and reaction energies, however, slightly less satisfactorily than DFTB3/3OB.
Authors:
 [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [4] ;  [5] ;  [2]
  1. Univ. of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education
  2. Karlsruhe Inst. of Technology (KIT) (Germany). Inst. of Physical Chemistry. Inst. of Biological Interfaces
  3. Karlsruhe Inst. of Technology (KIT) (Germany). Inst. of Physical Chemistry
  4. Claude Bernard Univ. Lyon 1, Villeurbanne (France). Inst. Light Material
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Sciences and Engineering Division. Chemical Sciences Division
Publication Date:
Grant/Contract Number:
AC05-00OR22725; INST 40/467-1 FUGG
Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Theory and Computation
Additional Journal Information:
Journal Volume: 14; Journal Issue: 1; Journal ID: ISSN 1549-9618
Publisher:
American Chemical Society
Research Org:
Karlsruhe Inst. of Technology (KIT) (Germany); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE; ORNL Laboratory Directed Research and Development (LDRD) Program; State of Baden-Wurttemberg (Germany); German Research Foundation (DFG)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1423039