LIBMBD METHOD: Difference between revisions

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Description: {{TAG|LIBMBD_METHOD}} selects one of the van der Waals methods available in the library libMBD of many-body dispersion methods{{cite|libmbd_1}}{{cite|libmbd_2}}{{cite|hermann:jcp:2023}}.
Description: {{TAG|LIBMBD_METHOD}} selects one of the van der Waals methods available in the library libMBD of many-body dispersion methods{{cite|libmbd_1}}{{cite|libmbd_2}}{{cite|hermann:jcp:2023}}.
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{{NB|important| This feature is available from VASP.6.3.0 onwards that needs to be compiled with [[Precompiler_options#-DUSELIBXC|-DUSELIBXC]].}}
{{NB|important| This feature is available from VASP.6.5.0 onwards that needs to be compiled with [[Precompiler_options#-DLibmbd|-DLibmbd]].}}
{{TAG|LIBXC1}} and {{TAG|LIBXC2}} can be set to a label (string) or number (integer) associated with a functional listed on the Libxc website{{cite|libxc_list}}, e.g., <code>GGA_X_PBE</code> and <code>101</code> for PBE exchange. The label indicates if this is an exchange (X), correlation (C), or exchange-correlation (XC) functional, and which family it belongs to, namely LDA (LDA or HYB_LDA), GGA (GGA or HYB_GGA) or meta-GGA (MGGA or HYB_MGGA). If {{TAG|LIBXC1}} corresponds to an exchange functional, then it can be used in combination with {{TAG|LIBXC2}} for the correlation functional.
{{TAG|LIBMBD_METHOD}} can be set to a label (string) corresponding to one of the methods listed on the libMBD website{{cite|libmbd_1}}, e.g., <code>GGA_X_PBE</code> and <code>101</code> for PBE exchange. The label indicates if this is an exchange (X), correlation (C), or exchange-correlation (XC) functional, and which family it belongs to, namely LDA (LDA or HYB_LDA), GGA (GGA or HYB_GGA) or meta-GGA (MGGA or HYB_MGGA). If {{TAG|LIBXC1}} corresponds to an exchange functional, then it can be used in combination with {{TAG|LIBXC2}} for the correlation functional.


Libxc is a separate library package that has to be downloaded{{cite|libxc}} and compiled before VASP is compiled with the corresponding [[Precompiler_options#-DUSELIBXC|precompiler options]] and [[Makefile.include#Libxc_.28optional.29|links to the libraries]].
Libxc is a separate library package that has to be downloaded{{cite|libxc}} and compiled before VASP is compiled with the corresponding [[Precompiler_options#-DUSELIBXC|precompiler options]] and [[Makefile.include#Libxc_.28optional.29|links to the libraries]].

Revision as of 10:31, 2 February 2024

LIBMBD_METHOD = [string] 

Description: LIBMBD_METHOD selects one of the van der Waals methods available in the library libMBD of many-body dispersion methods[1][2][3].


Important: This feature is available from VASP.6.5.0 onwards that needs to be compiled with -DLibmbd.

LIBMBD_METHOD can be set to a label (string) corresponding to one of the methods listed on the libMBD website[1], e.g., GGA_X_PBE and 101 for PBE exchange. The label indicates if this is an exchange (X), correlation (C), or exchange-correlation (XC) functional, and which family it belongs to, namely LDA (LDA or HYB_LDA), GGA (GGA or HYB_GGA) or meta-GGA (MGGA or HYB_MGGA). If LIBXC1 corresponds to an exchange functional, then it can be used in combination with LIBXC2 for the correlation functional.

Libxc is a separate library package that has to be downloaded[4] and compiled before VASP is compiled with the corresponding precompiler options and links to the libraries.

Calculations with Laplacian-dependent meta-GGA functionals and meta-GGA-based hybrid functionals are possible since VASP.6.4.0.

Warning: Do not use the Libxc functionals that are hybrid-MGGA-exchange-only, i.e., those whose label starts with HYB_MGGA_X, since the results will be wrong.
Important: To get correct results with meta-GGA functionals (see discussion at LTBOUNDLIBXC), it is necessary to use Libxc from version 5.2.0 onwards (or the master version for the latest implemented functionals) and to compile it with the option --disable-fhc.


Examples that use this tag

References