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LDOS and work function

Posted: Fri Dec 03, 2004 1:37 am
by a.soon
Dear all,
Can anyone tell me how to extract the local DOS and the work function be extracted from the calculation? I understand from the manual that LORBIT is the tag to play around with, but I tried values 1 and 12 and in vain.

With much appreciation.
Cheers!
Aloysius
:)

LDOS and work function

Posted: Tue Dec 07, 2004 12:50 am
by a.soon
Hi,
I have tried assessing the webpage but it seems like it does not exist anymore. IS there anyway that you could provide me whatz in there?
Thank you very much

Aloysius


[quote="whoming"]pls check this site.
http://cst-www.nrl.navy.mil/~Eerwin/vasptips/
there may be something useful to you.[/quote]

LDOS and work function

Posted: Tue Dec 07, 2004 3:43 am
by a.soon
I have tried again and found that this works
http://cst-www.nrl.navy.mil/~erwin/vasptips/

Cheers!

LDOS and work function

Posted: Mon Dec 13, 2004 9:06 pm
by a.soon
Hi all,
I understand that if one uses the USPP and wants to calculate the LDOS by setting LORBIT=T, then it appears that one can only use one CPU node to run the job.
Has anyone able to overcome this problem?
Cheers!

LDOS and work function

Posted: Tue Dec 14, 2004 10:55 am
by admin
Dear VASP-user,
**** LOCAL, l,m-decomposed DOS*****
for vasp.4.6, the local, lm decomposed DOS most conveniently can be obtained by setting
LORBIT = 1, 11 in INCAR
please mind that
-- LORBIT >= 10 applies for the PAW method only
-- you have to set RWIGS explicitely unless you use PAW potentials
the local, decomposed DOS will then be written in the SECOND block
of data in DOSCAR (the first block contains the E, total DOS and integrated total DOS),
the output of the second block will be ordered
E, lm-DOS for each l going from -m,...,0,...,+m , for each ion.
l-ordering: s, p_y, p_z, p_x, d_xy, d_yz, d_z2-r2, d_xz, d_x2-y2.
-- if ISPIN = 2, the spin-down component of the respective partial DOS
will follow the spin-up component immediately.

**** WORK FUNCTION ****
to calculate the workfunction,
LVTOT = .TRUE.
has to be set in INCAR.
A file LOCPOT will be generated, which contains the planar-averaged potential
of the slab (along the surface normal)
the work function Phi will then be evaluated from
Phi = V(vacuum) - E_fermi
with V(vacuum) ... potential in the center of the vacuum of the slab
E_fermi ... Ferni level (given in OUTCAR).
please be aware that the vacuum should be large enough to guarantee that the
potential has reached its _constant_ vacuum level.

for further reading please have a look at the tutorial file
handsonIII.pdf
which you can download from the VASP-workshop site
http://cms.mpi.univie.ac.at/vasp-workshop

LDOS and work function

Posted: Wed Dec 15, 2004 5:48 am
by a.soon
Thank you very much for the reply.
I believe now I have a better understanding of how to analyze these two files.

However, my question was with regards to computing the LDOS with the number of cpus. I believe the DOS was calculated fine with a single node but when I increased the number of nodes to more than one. The calculation does not run.
This is what I have experienced with the USPP. I have also tried with the PAW and things worked fine when the number of nodes used are more than one.

Cheers!

<span class='smallblacktext'>[ Edited Wed Dec 15 2004, 06:50AM ]</span>

LDOS and work function

Posted: Mon Apr 11, 2005 2:08 pm
by admin
concerning the LDOS:
if LORBIT is set, NPAR has to be set to 1
concerning the LOCPOT file:
please use the tool vtotav.f to plot the planar-averaged potential,
contact vasp.materialphysik@univie.ac.at
if you do not have access to that program

LDOS and work function

Posted: Thu Jan 24, 2013 8:30 am
by xx4751
Dear all,
I want to calculate the work function. I set LVTOT=.TRUE. in INCAR file to get the LOCPOT file, but there is a warning in out file."For LVTOT=.TRUE. VASP.5.x writes the TOTAL local potential to |
| the file LOCPOT. If you want the Hartree contributions only, use |
| LVHAR=.TRUE. instead. " . Could you tell me what did this mean and what can I do now. Thank you very much.

LDOS and work function

Posted: Tue Feb 18, 2014 1:36 pm
by cappri
Hello @xx4751 can you please provide me the INCAR file you setup for work function calculations?