Exchange-Correlation functionals#
The exchange-correlation functional is specified in the CLUSTER and/or SYMBOL files. The user can choose to use LDA, GGA, and MGGA functionals. Here is a table with recognized functionals:
Functionals |
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|---|---|---|---|---|
RPA |
WIGNER |
GUNLUN |
PW91 |
PBE |
REVPBE |
RPBE |
B88 |
SCAN |
MSCAN |
RSCAN |
R2SCAN |
PBEIBP |
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How to input the functionals?#
The functional string are composed of their type, followed by a dash (-), and followed by their name.For example,
LDA-PW91 or GGA-PBE can be written in the input files.
Additionally, the functional for exchange and correlation can be specified individually. The asterisk (*) separates
the functionals. For example, LDA-PW91*LDA-PW91 says to use PW91 on both the Exchange and Correlation.
If the user wants to run GGA-PBE exchange-only, for example, the string will be GGA-PBE*GGA-NONE