PMID- 27352028
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180207
LR  - 20180207
IS  - 1361-648X (Electronic)
IS  - 0953-8984 (Linking)
VI  - 28
IP  - 33
DP  - 2016 Aug 24
TI  - A quantum-mechanics molecular-mechanics scheme for extended systems.
PG  - 335201
LID - 10.1088/0953-8984/28/33/335201 [doi]
AB  - We introduce and discuss a hybrid quantum-mechanics molecular-mechanics (QM-MM) 
      approach for Car-Parrinello DFT simulations with pseudopotentials and planewaves 
      basis, designed for the treatment of periodic systems. In this implementation the 
      MM atoms are considered as additional QM ions having fractional charges of either 
      sign, which provides conceptual and computational simplicity by exploiting the 
      machinery already existing in planewave codes to deal with electrostatics in 
      periodic boundary conditions. With this strategy, both the QM and MM regions are 
      contained in the same supercell, which determines the periodicity for the whole 
      system. Thus, while this method is not meant to compete with non-periodic QM-MM 
      schemes able to handle extremely large but finite MM regions, it is shown that 
      for periodic systems of a few hundred atoms, our approach provides substantial 
      savings in computational times by treating classically a fraction of the 
      particles. The performance and accuracy of the method is assessed through the 
      study of energetic, structural, and dynamical aspects of the water dimer and of 
      the aqueous bulk phase. Finally, the QM-MM scheme is applied to the computation 
      of the vibrational spectra of water layers adsorbed at the TiO2 anatase (1 0 1) 
      solid-liquid interface. This investigation suggests that the inclusion of a 
      second monolayer of H2O molecules is sufficient to induce on the first adsorbed 
      layer, a vibrational dynamics similar to that taking place in the presence of an 
      aqueous environment. The present QM-MM scheme appears as a very interesting tool 
      to efficiently perform molecular dynamics simulations of complex condensed matter 
      systems, from solutions to nanoconfined fluids to different kind of interfaces.
FAU - Hunt, Diego
AU  - Hunt D
AD  - Departamento de Quimica Inorganica, Analitica y Quimica Fisica/INQUIMAE, Facultad 
      de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad 
      Universitaria, Pab. II, Buenos Aires (C1428EHA) Argentina.
FAU - Sanchez, Veronica M
AU  - Sanchez VM
FAU - Scherlis, Damian A
AU  - Scherlis DA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20160628
PL  - England
TA  - J Phys Condens Matter
JT  - Journal of physics. Condensed matter : an Institute of Physics journal
JID - 101165248
EDAT- 2016/06/29 06:00
MHDA- 2016/06/29 06:01
CRDT- 2016/06/29 06:00
PHST- 2016/06/29 06:00 [entrez]
PHST- 2016/06/29 06:00 [pubmed]
PHST- 2016/06/29 06:01 [medline]
AID - 10.1088/0953-8984/28/33/335201 [doi]
PST - ppublish
SO  - J Phys Condens Matter. 2016 Aug 24;28(33):335201. doi: 
      10.1088/0953-8984/28/33/335201. Epub 2016 Jun 28.