Reasonable charges?

Bader charge density analysis

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anna_90
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Joined: Wed Dec 21, 2011 2:21 pm

Reasonable charges?

Post by anna_90 »

I have used the Bader analysis using chgsum.pl using AECCAR0 and AECCAR2, and then submitted this using bader CHGCAR -ref CHGCAR_sum. My ACF.dat file is below, but I'm not sure how reasonable they are, as the charges all seem quite low.
# X Y Z CHARGE MIN DIST ATOMIC VOL
--------------------------------------------------------------------------------
1 0.0000 0.0000 0.0000 2.0674 0.9234 7.5251
2 0.0000 0.0000 2.8448 3.1595 0.8890 7.1900
3 0.0000 0.0000 5.4809 3.1595 0.8890 7.1900
4 0.0000 4.6167 0.0000 3.1457 0.8966 7.3057
5 0.0000 4.6167 2.7742 3.1461 0.8959 7.2770
6 0.0000 4.6167 5.5516 3.1461 0.8959 7.2770
7 4.6167 0.0000 0.0000 3.1457 0.8966 7.3057
8 4.6167 0.0000 2.7742 3.1461 0.8959 7.2770
9 4.6167 0.0000 5.5516 3.1461 0.8959 7.2770
10 4.6167 4.6167 0.0000 3.1559 0.8966 7.3241
11 4.6167 4.6167 2.7453 3.1451 0.8890 7.2410
12 4.6167 4.6167 5.5805 3.1451 0.8890 7.2410
13 2.3176 2.3176 1.4167 3.1295 0.8877 7.2142
14 2.3051 2.3051 4.1629 3.1621 0.8987 7.2986
15 2.3176 2.3176 6.9091 3.1295 0.8877 7.2142
16 2.2949 6.9385 1.3918 3.1387 0.8947 7.2661
17 2.3425 6.8909 4.1629 3.1467 0.8995 7.2575
18 2.2949 6.9385 6.9340 3.1387 0.8947 7.2661
19 6.9385 2.2949 1.3918 3.1387 0.8947 7.2661
20 6.8909 2.3425 4.1629 3.1467 0.8995 7.2575
21 6.9385 2.2949 6.9340 3.1387 0.8947 7.2661
22 6.9158 6.9158 1.4167 3.1295 0.8877 7.2142
23 6.9283 6.9283 4.1629 3.1621 0.8987 7.2986
24 6.9158 6.9158 6.9091 3.1295 0.8877 7.2142
25 1.4189 1.4189 0.0000 6.9395 0.8753 11.3713
26 1.3784 1.3784 2.7688 6.9313 0.8733 11.1283
27 1.3784 1.3784 5.5570 6.9313 0.8733 11.1283
28 1.3730 6.0008 0.0000 6.9309 0.8838 11.2002
29 1.3833 5.9833 2.7768 6.9253 0.8820 11.1013
30 1.3833 5.9833 5.5489 6.9253 0.8820 11.1013
31 6.0008 1.3730 0.0000 6.9309 0.8838 11.2002
32 5.9833 1.3833 2.7768 6.9253 0.8820 11.1013
33 5.9833 1.3833 5.5489 6.9253 0.8820 11.1013
34 5.9927 5.9927 0.0000 6.9293 0.8962 11.1857
35 5.9860 5.9860 2.7777 6.9228 0.8690 11.0644
36 5.9860 5.9860 5.5480 6.9228 0.8690 11.0644
37 3.2407 3.2407 0.0000 6.9293 0.8962 11.1857
38 3.2475 3.2475 2.7777 6.9228 0.8690 11.0644
39 3.2475 3.2475 5.5480 6.9228 0.8690 11.0644
40 3.2326 7.8604 0.0000 6.9305 0.8838 11.1974
41 3.2501 7.8501 2.7768 6.9251 0.8820 11.1003
42 3.2501 7.8501 5.5489 6.9251 0.8820 11.1003
43 7.8604 3.2326 0.0000 6.9305 0.8838 11.1974
44 7.8501 3.2501 2.7768 6.9251 0.8820 11.1003
45 7.8501 3.2501 5.5489 6.9251 0.8820 11.1003
46 7.8146 7.8146 0.0000 6.9395 0.8753 11.3713
47 7.8550 7.8550 2.7688 6.9313 0.8733 11.1283
48 7.8550 7.8550 5.5570 6.9313 0.8733 11.1283
49 0.9353 3.6914 1.3902 6.9242 0.8765 11.1238
50 0.9316 3.6802 4.1629 6.9314 0.8818 11.1570
51 0.9353 3.6914 6.9355 6.9242 0.8765 11.1238
52 0.9332 8.3002 1.4399 6.9495 0.8956 11.3636
53 0.9550 8.2784 4.1629 6.9228 0.8682 11.0734
54 0.9332 8.3002 6.8858 6.9495 0.8956 11.3636
55 5.5528 3.6807 1.3915 6.9256 0.8771 11.1235
56 5.5395 3.6939 4.1629 6.9277 0.8931 11.0725
57 5.5528 3.6807 6.9342 6.9256 0.8771 11.1235
58 5.5420 8.2982 1.3902 6.9242 0.8765 11.1238
59 5.5532 8.3018 4.1629 6.9314 0.8818 11.1570
60 5.5420 8.2982 6.9355 6.9242 0.8765 11.1238
61 3.6914 0.9353 1.3902 6.9242 0.8765 11.1238
62 3.6802 0.9316 4.1629 6.9318 0.8818 11.1598
63 3.6914 0.9353 6.9355 6.9242 0.8765 11.1238
64 3.6807 5.5528 1.3915 6.9256 0.8771 11.1235
65 3.6939 5.5395 4.1629 6.9282 0.8931 11.0753
66 3.6807 5.5528 6.9342 6.9256 0.8771 11.1235
67 8.3002 0.9332 1.4399 6.9495 0.8956 11.3636
68 8.2784 0.9550 4.1629 6.9233 0.8682 11.0765
69 8.3002 0.9332 6.8858 6.9495 0.8956 11.3636
70 8.2982 5.5420 1.3902 6.9242 0.8765 11.1238
71 8.3018 5.5532 4.1629 6.9318 0.8818 11.1598
72 8.2982 5.5420 6.9355 6.9242 0.8765 11.1238
--------------------------------------------------------------------------------
VACUUM CHARGE: 0.0000
VACUUM VOLUME: 0.0000
NUMBER OF ELECTRONS: 407.0000

The system is TiV23O48.
graeme
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Re: Reasonable charges?

Post by graeme »

This looks reasonable; the metal atoms have (roughly) a net charge of +2 and the oxygen atoms are -1.
anna_90
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Joined: Wed Dec 21, 2011 2:21 pm

Re: Reasonable charges?

Post by anna_90 »

Can I ask how you worked that out? I thought you took away the charge from the number of valence electrons, but when I do this for CeO2, I have Ce as a negative ion, which is surely wrong? This is the output for CeO2:

X Y Z CHARGE MIN DIST ATOMIC

0 0 0 9.699 1.2396 15.4635
0 2.7325 2.7325 9.699 1.2396 15.4636
2.7325 0 2.7325 9.699 1.2396 15.4635
2.7325 2.7325 0 9.699 1.2396 15.4636
1.3663 1.3663 1.3663 7.1503 1.0333 12.6683
4.0988 4.0988 1.3663 7.1505 1.0333 12.6706
4.0988 1.3663 4.0988 7.1505 1.0333 12.6707
1.3663 4.0988 4.0988 7.1503 1.0333 12.6682
1.3663 1.3663 4.0988 7.1509 1.0333 12.6764
4.0988 4.0988 4.0988 7.1503 1.0333 12.6678
4.0988 1.3663 1.3663 7.1503 1.0333 12.6678
1.3663 4.0988 1.3663 7.1509 1.0333 12.6764

So 4- 9.699 = -5.7199?
Thanks!
graeme
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Re: Reasonable charges?

Post by graeme »

You have to compare the Bader charges to the number of electrons listed (grep for ZVAL) in the POTCAR file. For Ce, it is probably 12, giving a charge of 12-9.7 = 2.3. The charge on oxygen (ZVAL=6) is 6 - 7.15 = -1.15. Again, the 2:1 ratio of charge makes sense.
anna_90
Posts: 3
Joined: Wed Dec 21, 2011 2:21 pm

Re: Reasonable charges?

Post by anna_90 »

Thank you very much!
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