[Wien] Gap calculated with GGA+U, mBJ and HF

[tran at theochem.tuwien.ac.at]

HF is absolutely not reliable for band gap, since it is well known
to overestimate it by a large amount.

On Monday 2017-08-07 01:32, Wien2k User wrote:

>Date: Mon, 7 Aug 2017 01:32:04
>From: Wien2k User <wien2k.user at gmail.com>
>Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
>To: wien at zeus.theochem.tuwien.ac.at
>Subject: [Wien] Gap calculated with GGA+U, mBJ and HF
>
>Dear Wien2k users;
>
>I calculated the gap of a material whose experimental value is unknown.
>
>With GGA+U, mBJ potential and GW, I found that this material is semimetal (a slight band overlap) but with HF i found it to be semiconductor of very small gap.
>
>How can I know what is the real nature of the gap of this material?
>
>This calculation is a part of a future paper so I have to put all found  results (GGA + U, mBJ, GW and HF) in spite of what give deferent nature or I have to adopt that of the HF since it
>is a more accurate method?
>
>