ZGNR charge transfer from Mulliken Population-reg

[GJK]

Dear all,

Here with I have attached the Mulliken population file of
1. Hydrogen Passivated ZGNR
2.Isolated Biomolecule
3.Combined system of ZGNR and biomolecule

Question No 1:
Kindly help me in finding the total charge transfer between the molecule and ZGNR.

Question No 2:
As I have attached the biomolecule to ZGNR carbon atom via Nitrogen atom,I need to find the charge transfer between the carbon and nitrogen atom whose positions  in the Mulliken population report for the three sytems mentioned above are as follows;
1. Hydrogen Passivated ZGNR (Carbon Number:54)
2.Isolated Biomolecule(Nitrogen Number:0)
3.Combined system of ZGNR and biomolecule(Carbon Number:54 and Nitrogen Number:79)

Note; Already I have verified the links provided by you for the charge transfer.
http://www.tcm.phy.cam.ac.uk/castep/documentation/WebHelp/extfile/castep_tuts/html/castep_dens_diff_tut.htm
http://vaspnotes.blogspot.jp/2013/10/charge-density-difference-plots.html

Question 3:


Your kind assistance will be helpful.: From these links I understood that we should calculate the electron density and take the difference for overall charge transfer between the two systems.How to get the electron density value from the colour mapping.It is showing a range of values.Already I know that isovalue=electron density.(Most molecular modeling software packages allow the user to choose a value for the electron density, often called the IsoValue.http://en.wikipedia.org/wiki/Electron_density). How to get the electron density value for my system so that I can easily calculate the charge transfer from the formula given by you???

[GJK]

Dear Dr.Anders,

Kindly resolve my issue.