Band decomposed chargedensity for Spinpolarized calculation (magnetic system)

[giacomo giorgi]

Hi everybody,
I have a doubt.

I want to plot my HOMO and LUMO.

In caseof a spin unpolarized system, I think I have no problem and I can use

LPARD=.TRUE.
LSEPB=.TRUE.
LSEPK=.TRUE.
IBAND=110 111 ! HOMO AND LUMO
KPUSE=1 ! on Gamma

What about in the case of a spinpolarized calculation?
I mean, in my particular case I have that the VB of the system is the 110th spin-up while the CB is the 88th spin-down. A magnetic and spin polarized system, Mn-based.

Moreover I have two different spin components, so plotting with the above tags it seems not feasible.

How to plot from the same calculation HOMO AND LUMO at different spin?

Best,
G

[grybos]

The post is rather old, but maybe somebody else has a similar problem.

For spin-polarized systems, VASP prints two sets of data in CHGCAR and PARCHG (and maybe in other files too). First set is for the total charge density (alpha+beta) and the second is for "magnetization" (alpha-beta). Plotting programs (like p4vasp) usually use just the first set. You can split the file by hand, or use this simple script below (just copy it into a file and make it executable):

---------------------------
#!/bin/bash
#Script for splitting PARCHG files into total and magnetization components
#Robert Grybos 04.2012
#
#Arguments:$1 - input file name
#
awk -v file=$1 'NF==0{stat++}\
{if(stat==0) print $0 > file".tot"; print $0 > file".magn"};\
if(stat==1) print $0 >> file".tot";\
if(stat==2) print $0 >> file".magn"}' $1
----------------------


The script take a filename as argument and produces filename.tot and filename.magn files. Works for PARCHG, should work for CHGCAR, but I didn't test it.

To get alpha and beta spin components, you need to add/substract data in those files: alpha = tot + magn , beta = tot - magn , but I don't have a script for that yet.

<span class='smallblacktext'>[ Edited Wed Apr 04 2012, 11:54AM ]</span>