[Pw_forum] Lowdin charge problem

[loc duong ding]

Dear QE users,

I try to analysis the atomic charge. I found that Lowdin charge analysis can be implemeted by QE. I dod a test with NO2. I get the the result as following:

Lowdin Charges:
     Atom #   1: total charge =   4.5377, s =  1.2595, p =  3.2782,
                 spin up      =   2.4718, s =  0.7016, p =  1.7701,
                 spin down    =   2.0659, s =  0.5578, p =  1.5081,
                 polarization =   0.4058, s =  0.1438, p =  0.2620,
     Atom #   2: total charge =   6.1075, s =  1.7256, p =  4.3818,
                 spin up      =   3.1926, s =  0.8642, p =  2.3284,
                 spin down    =   2.9149, s =  0.8614, p =  2.0534,
                 polarization =   0.2777, s =  0.0027, p =  0.2749,
     Atom #   3: total charge =   6.1113, s =  1.7254, p =  4.3859,
                 spin up      =   3.1939, s =  0.8641, p =  2.3298,
                 spin down    =   2.9174, s =  0.8613, p =  2.0561,
                 polarization =   0.2765, s =  0.0028, p =  0.2737,

The strange thing is that the total charge of all atom is ~16.7 instead of 17 in NO2 molecules. 

Can you give me some instructions or explanation to fix this problem?

I great appreciate your help.

Sincerely, -----------------------------------------------
Loc Duong Dinh
Ms-Ph.D Student
Sungkyunkwan Advanced Institute of Nanotechnology,
Sungkyunkwan University,
Suwon, 440-746, Korea 
Email: mambom1902 at yahoo.com, ddloc at skku.edu