Queries about input and output files, running specific calculations, etc.
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rxk900
- Newbie

- Posts: 1
- Joined: Thu Nov 21, 2019 8:58 am
#1
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by rxk900 » Fri Nov 06, 2026 11:50 am
Hello,
I am currently wanting run some CAM-B3LYP calculations using VASP 6.6.1 linked to libxc.7.0.0. This combination should be capable of running this type of calculation.
However it is not clear what the values of some parameters should be. What are the correct values of the parameters AEXX, BEXX and HFSCREEN, and are there any other values which need to be set. For example do you set LMODELHF?
thanks
Rika
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alexey.tal
- Global Moderator

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- Joined: Mon Sep 13, 2021 12:45 pm
#2
Post
by alexey.tal » Fri Nov 06, 2026 2:24 pm
Dear Rika,
Thank you for your question.
You can run a CAM-B3LYP calculation by setting the following parameters in VASP:
Code: Select all
XC = HYB_GGA_XC_CAM_B3LYP
LHFCALC = .TRUE.
LMODELHF = .TRUE.
AEXX = 0.65 #Fraction of long-range exact exchange = alpha+beta = 0.65
BEXX = 0.19 #Fraction of short-range exact exchange = alpha = 0.19
HFSCREEN = 0.62361 #Screening = 0.33 in Bohr^{-1}
where alpha and beta correspond to Eq. (7) of 10.1016/j.cplett.2004.06.011.
Best,
Alexey