Dear Sir,

MEP and MESP both are same. Molecular electrostatic Potential is sometime called as MEP or MESP or ESP. It can be done by using the keyword pop=chelpg (it means that charges from electrostatic potential gradient) or by using pop=chelp (charges from electrostatic potential) in the route section. may i hope this help you.

with best wishes,

T. karthick

Dear karthick,

Thanks for your kind reply. I will try with the keyword you have given.

Regards,

V.Ragavendran

Dear Venkatesan,

They are same both. It can be used to find what region of molecule is electron rich or poor to have an interpretation what side of molecule is apt for nucleophilic or electrophilic attack, or in other word what side of molecule can act as a Lewis acid or base.  To have more please read Dr. Politzer and Murray article. Also, I think WFA-SAS is a suitable software for calculation of MESP.

Best wishes,

Sirous

From the MESP calculation, You can find the distribution of the negative and positive potential over the molecule. It can be obtained from the cube file of the gaussian job.

From the MESP calculation, You can find the distribution of the negative and positive potential over the molecule. It can be obtained from the cube file of the gaussian job.