Graphite TS binding energy: Difference between revisions
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Description: determine the interlayer binding energy of graphite in its experimental structure using the method | Description: determine the interlayer binding energy of graphite in its experimental structure using the method | ||
of Tchatchenko and Scheffler to account for van der Waals interactions. | of Tchatchenko and Scheffler to account for van der Waals interactions. |
Revision as of 15:09, 2 May 2017
Description: determine the interlayer binding energy of graphite in its experimental structure using the method of Tchatchenko and Scheffler to account for van der Waals interactions.
Semilocal DFT at the GGA level underestimates long-range dispersion interactions. In the case of graphite, PBE predicts the interlayer binding energy of ~1 meV/atom which is too small compared to the RPA reference of 0.048 eV/atom (Lebgue et al., PRL 105, 195401 (2010)).
In this example, the interlayer binding energy of graphite in its experimental structure is determined using the TS method of Tchatchenko and Scheffler (PRL 102, 073005 (2009)), which performs well in description of the structure of graphite (see e.g. example graphiteDistance_ts).
The calculation is performed in two steps (sigle-point calculations) in which the energy for bulk graphite and for graphene are obtained. The binding energy is computed automatically and it is written in the file results.dat.
Even though the TS method predicts a reasonable geometry it overestimates the energetics strongly: the computed binding energy of -0.083 eV/atom is too large compared to the RPA reference of 0.048 eV/atom This overestimation is - at least in part - due to neglecting the many-body interactions (see example graphiteBinding_mbd).
Details of implementation of TS in VASP + a number of tests: Bucko et al., PRB 87, 064110 (2013).
Used INCAR Tags
ALGO, EDIFF, EDIFFG, IBRION, ISIF, ISMEAR, IVDW, LCHARG, LVDW_EWALD, LWAVE, NPAR, NSW, PREC, SIGMA
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