Bader charge with PVDF

Bader charge density analysis

Moderator: moderators

Post Reply
ddloc84
Posts: 10
Joined: Fri Oct 26, 2012 1:05 am

Bader charge with PVDF

Post by ddloc84 »

I try to calculate charge on atoms of PVDF -(CH2-CF2)- with beta-phase. I using Vasp and Bader charge analysis.
I did as instructions in the website of Bader charge. (using chgsum.pl to get CHGCAR_sum and use it as reference)
The result is:
C 1 3.2430 -0.6250 13.1940 2.7960 0.3372 4.0399
C 2 6.4531 1.1920 12.3570 4.0259 0.5742 12.7823
C 3 5.3750 0.6020 13.1930 2.7977 0.3406 4.0380
C 4 4.3210 -0.0330 12.3570 4.0355 0.5716 13.0279
F 5 4.8390 1.5330 14.0100 7.6209 0.7728 51.5659
F 6 5.9260 -0.3540 14.0210 7.5808 0.7930 49.9952
F 7 2.7020 0.3080 14.0050 7.6151 0.7751 46.7961
F 8 3.7940 -1.5760 14.0280 7.5875 0.7976 57.1816
H 9 6.9091 0.4010 11.7390 1.0087 0.3334 40.2202
H 10 1.7500 -0.4990 11.7080 0.9658 0.2814 49.2300
H 11 4.7710 -0.8170 11.7270 1.0002 0.3394 45.0695
H 12 3.8740 0.7430 11.7190 0.9658 0.2882 44.9785

In principle, the charge at H should be positive but it is not the case in Bader analysis.

Could you please give me some instructions how to understand and solve this problem? I do not know the origin of the error from my calculation.

I would like to thanks for all your help.

Best regard,
Loc.
graeme
Site Admin
Posts: 2256
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: Bader charge with PVDF

Post by graeme »

Charges on H close to 1 look very reasonable.
ddloc84
Posts: 10
Joined: Fri Oct 26, 2012 1:05 am

Re: Bader charge with PVDF

Post by ddloc84 »

Thank you for your comments.

Although the charge on H is nearly 1, It should be smaller than 1. PVDF have strong dipole originated from negative F and positive H. Bader charge is so strange. I have check by Mulliken charge and Hirschfeld charge. Both of them are contracted to Bader charge analysis.

I am still struggling.

Could anyone give me some comments?

Best regards,
Loc.
Post Reply