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QuantumATK => General Questions and Answers => Topic started by: Ambika kumari on June 7, 2022, 13:36

Title: charge transfer calculation
Post by: Ambika kumari on June 7, 2022, 13:36
How to calculate charge transfer. I calculated mulliken population. How to analyse it, what amount of charge is transfered to/from gas? I am sensing carbon monoxide on OH terminated graphene nanoribbon .I am attaching file here please help,.
If there is other way to calculate the charge transfer,then guide me.
Title: Re: charge transfer calculation
Post by: AsifShah on June 7, 2022, 14:40
You will need to compare it with pristine case. Eg in normal conditions carbon has ideal charge of 4 & hydrogen has 1 & oxygen has 6 so on.. Now u can check which atoms in ur current file have changed their charge & compare it with the ideal charge.
Title: Re: charge transfer calculation
Post by: Ambika kumari on June 7, 2022, 16:05
 Before adsorption of CO gas, in CO gas  carbon has 4e and oxygen has 6e so net charge is 10e . After adsorption O has 5.802e and C has 4.193e then total charge is 9.995e.
delQ= 9.995-10=-0.005e that mean CO gas is withdrawing 0.005 charge from AGNR ? Am I right?

QAKT  staff kindly also verify it.
Title: Re: charge transfer calculation
Post by: Ambika kumari on June 8, 2022, 08:31
Anyone reply please?
Title: Re: charge transfer calculation
Post by: AsifShah on June 8, 2022, 14:35
Firstly, I doubt the charge on C & O after adsorption because oxygen is more electronegative than carbon so charge should be flowing to oxygen from carbon but maybe I am missing something here. Recheck it else NVM.
Secondly, If CO charge charge has reduced it means AGNR has taken some charge from CO, (Here I suggest to see electron density 1D plot & see the minimum electron density in bonding region which should give u idea of how much CO is interacting with AGNR. It looks the charge transfer is not much happening here.
Title: Re: charge transfer calculation
Post by: Ambika kumari on June 9, 2022, 16:13
Thanks for helping.
I am trying to solve it.
Title: Re: charge transfer calculation
Post by: AsifShah on June 9, 2022, 18:22
It is okay. I suggest to read some literature on Mulliken charge as it is not reliable in some cases & some people report other methods. For intro look into "Chemlibre Mulliken Charge" in Google.
Title: Re: charge transfer calculation
Post by: Ambika kumari on June 10, 2022, 08:28
I know it is not reliable. I dont know the code for  other charge transfer method.
Thanks for advice, I use it.