Dear Hooman,
You need to put Mn1 and Mn2 first in the atomic list and then the remaining
atoms, like this:
ATOMIC_POSITIONS {crystal}
Mn1 0.000000000 0.000000000 0.000000000
Mn1 0.500000000 0.500000000 0.000000000
Mn2 -0.000000000 0.500000000 -0.000000000
Mn2 0.500000000 0.000000000 0.000000000
O 0.138178100 0.392913471 0.233700489
O 0.361767139 0.106848852 0.766122199
Li 0.250095079 0.250498471 0.500248603
O 0.138177233 0.892913211 0.233699914
O 0.361766394 0.606847636 0.766121721
Li 0.250092166 0.750492217 0.500245834
O 0.638233606 0.393152364 0.233878279
O 0.861822767 0.107087789 0.766300086
Li 0.749907834 0.249508783 0.499754166
O 0.638233861 0.893152148 0.233877801
O 0.861822900 0.607086529 0.766299511
Li 0.749905921 0.749501529 0.499751397
This is so because the HP code expects that in the list of atoms you first have
Hubbard atoms (i.e. with U) and then all the rest (no U). This is just how the
code works.
> looks like you are applying U twice for Mn atom. what's the difference
> between Mn1 and Mn2 site?. different symmetry?
As Hooman said, Mn1 has a starting magnetization positive, and Mn2 has a
starting magnetization negative. This means that essentially we are having two
sub-lattices, which is needed to model the antiferromagnetic ordering. In this
case I think that Mn1 and Mn2 are crystallographically equivalent, so the U
values will be the same for both types of Mn, as Human said. But in general, in
other cases, Mn1 and Mn2 may also be crystallographically slightly different
and hence the resulting U will also be somewhat different.
If you are interested, you may have a look at these two papers about
site-dependent U values (e.g. when there are O vacancies):
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.094102
https://arxiv.org/abs/2001.06540
Greetings,
Iurii
--
Dr. Iurii Timrov
Postdoctoral Researcher
STI - IMX - THEOS and NCCR - MARVEL
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: users <[email protected]> on behalf of Hooman
Yaghoobnejad Asl <[email protected]>
Sent: Friday, February 21, 2020 10:05:52 PM
To: Manu Hegde
Cc: Quantum ESPRESSO users Forum
Subject: Re: [QE-users] Missing Hubbard atoms from ATOMIC_POSITIONS card
The two U terms applied to the two crystallographically distinct Mn atoms
(opposite spin arrangement). Still, I'm expecting to get similar values for
both as they are in chemically identical environments, similar to the NiO
reference.
Thanks,
Hooman
On Fri, Feb 21, 2020 at 2:29 PM Manu Hegde
<[email protected]<mailto:[email protected]>> wrote:
looks like you are applying U twice for Mn atom. what's the difference between
Mn1 and Mn2 site?. different symmetry?. you may have to think about it.
Manu
On Fri, Feb 21, 2020 at 2:45 PM Hooman Yaghoobnejad Asl
<[email protected]<mailto:[email protected]>> wrote:
Dear all,
The following must be an easy fix. I just started to use hp.x for LiMnO2
(hypothetical structure), which is a magnetic (AFM) insulator. I followed the
example02 of the HP code (NiO U parameter) and it worked as expected. I do the
same sequence for the above structure (i.e., magnetic metal, magnetic
insulator, linear response), but at the last step, hp.x stops with the
following error:
" WARNING! All Hubbard atoms must be listed first in the ATOMIC_POSITIONS
card of PWscf
Stopping..."
Any hint to show me what I'm doing wrong is highly appreciated.
I'm using QE 6.4.1
Input for the second step (magnetic insulator) is pasted below:
&SYSTEM
ibrav = 0
celldm(1) = 10.52955401,
nat = 16
ntyp = 4
nbnd = 72
ecutwfc = 50 ,
ecutrho = 400 ,
occupations = 'fixed' ,
nspin = 2 ,
tot_magnetization = 0.00
lda_plus_u = .true.,
lda_plus_u_kind = 0,
U_projection_type = 'ortho-atomic',
Hubbard_U(2) = 1.d-8
Hubbard_U(3) = 1.d-8
/
&ELECTRONS
electron_maxstep = 500,
conv_thr = 1.d-15
mixing_beta = 0.7 ,
startingpot = 'file'
startingwfc = 'file'
/
ATOMIC_SPECIES
O 15.99 O.pbe-n-kjpaw_psl.0.1.upf
Mn1 54.93805 Mn.pbe-spn-kjpaw_psl.0.3.1.UPF
Mn2 54.93805 Mn.pbe-spn-kjpaw_psl.0.3.1.UPF
Li 6.94100 Li.pbe-s-kjpaw_psl.0.2.1.upf
ATOMIC_POSITIONS {crystal}
O 0.138178100 0.392913471 0.233700489
O 0.361767139 0.106848852 0.766122199
Mn1 0.000000000 0.000000000 0.000000000
Li 0.250095079 0.250498471 0.500248603
O 0.138177233 0.892913211 0.233699914
O 0.361766394 0.606847636 0.766121721
Mn2 -0.000000000 0.500000000 -0.000000000
Li 0.250092166 0.750492217 0.500245834
O 0.638233606 0.393152364 0.233878279
O 0.861822767 0.107087789 0.766300086
Mn2 0.500000000 0.000000000 0.000000000
Li 0.749907834 0.249508783 0.499754166
O 0.638233861 0.893152148 0.233877801
O 0.861822900 0.607086529 0.766299511
Mn1 0.500000000 0.500000000 0.000000000
Li 0.749905921 0.749501529 0.499751397
CELL_PARAMETERS (alat)
0.994008748 0.006054947 0.149445159
-0.494775805 0.989385379 -0.097973510
0.114248343 -0.030106079 0.902638553
K_POINTS automatic
4 4 5 0 0 0
--
Hooman Yaghoobnejad
PhD, Department of Chemistry
Missouri University of Science and Technology
Rolla, MO 65409
USA
--
Hooman Yaghoobnejad
PhD, Department of Chemistry
Missouri University of Science and Technology
Rolla, MO 65409
USA
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