How do I calculate accurate DOS?

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


Moderators: Global Moderator, Moderator

Locked
Message
Author
sch28181
Newbie
Newbie
Posts: 3
Joined: Fri Feb 12, 2010 6:18 am

How do I calculate accurate DOS?

#1 Post by sch28181 » Fri Feb 12, 2010 6:39 am

I want to calculate DOS of Pd(111) system.
At first I optimized 3layer 3x3 Pd system.
With optimized system, I tried to do DOS calculation.
This is my INCAR file.

NWRITE = 2; LPETIM=F

ISTART = 0 job : 0-new 1-cont 2-samecut

ICHARG = 2 charge: 1-file 2-atom 10-const

INIWAV = 1 electr: 0-lowe 1-rand

NGX = 46 ; NGY = 46 ; NGZ = 94
Electrronic Relaxation 1

NELM = 100; NELMIN = 4

PREC = Normal
EDIFF = 1E-05 stopping criterion for ELM
ENCUT = 270

Ionic Relaxation

LCORR = T Harris-correction to forces
LORBIT = 10
GGA = 91
DOS related values

ISMEAR = -5; SIGMA = 0.2
LWAVE = .FALSE.

Kpoint is

K-Points
0
Gamma
9 9 1
0 0 0

But the result was different from reference.
In my calculation the result was not a smooth curve.
But there are many sharp peaks.
What is the problem?
Last edited by sch28181 on Fri Feb 12, 2010 6:39 am, edited 1 time in total.

zoowe
Newbie
Newbie
Posts: 26
Joined: Thu Jan 21, 2010 11:41 pm
License Nr.: 5-100
Location: USA

How do I calculate accurate DOS?

#2 Post by zoowe » Fri Feb 12, 2010 1:27 pm

you should look into the manual. There is a section called Accurate Band, DOS.
Last edited by zoowe on Fri Feb 12, 2010 1:27 pm, edited 1 time in total.

sch28181
Newbie
Newbie
Posts: 3
Joined: Fri Feb 12, 2010 6:18 am

How do I calculate accurate DOS?

#3 Post by sch28181 » Mon Feb 15, 2010 2:08 am

what is the difference between SC calculation and non-SC calculation?
Last edited by sch28181 on Mon Feb 15, 2010 2:08 am, edited 1 time in total.

physicalattraction
Newbie
Newbie
Posts: 44
Joined: Wed May 21, 2008 1:47 pm
License Nr.: 916
Location: Eindhoven, The Netherlands

How do I calculate accurate DOS?

#4 Post by physicalattraction » Tue Feb 16, 2010 3:29 pm

In a non-self-consistent calculation, you need to input the position of the charges (i.e. charge density, supplied in the CHGCAR file) and these will be fixed during the run. It might be that the charge density you supply is not consistent with the ground state of the system. In a self-consistent run, VASP would update the charge density, but in a non-self-consistent run, the charge density is kept fixed.
Last edited by physicalattraction on Tue Feb 16, 2010 3:29 pm, edited 1 time in total.

boris
Full Member
Full Member
Posts: 106
Joined: Wed Jan 16, 2008 1:27 pm
License Nr.: 567
Location: France

How do I calculate accurate DOS?

#5 Post by boris » Wed Feb 17, 2010 7:14 am

And so to get an accurate DOS calculation, you first perform a self-consistent calculation in order to let VASP determine the ground state charge density, then you perform a non-self-consistent calculation (ICHARG = 11) to determine the accurate DOS.
Last edited by boris on Wed Feb 17, 2010 7:14 am, edited 1 time in total.

Locked