Subject: G98: Oniom energies

From: Dr Reinaldo Pis Diez <[email-masked]>
Date: Tue, 18 Jul 2000 04:06:56 -0300

Dear ccl'ers,

		I'm doing some calculations using the oniom method as implemented in g98. 
		My system is a 30-atoms organic molecule surrounded by almost hundred
solvent molecules. I'm using dft/mm (svwn:uff) for higher and lower layers,
respectively. 
		The first calculation seems to be a mm one giving an energy which I call
E_3.
		Then, the program jumps into the dft job achieving self consistency with
an energy E_scf.
		As a third step, it enters into another job having less electrons than
the higher layer, organic molecule, giving an energy E_1.   
		Finally, the program enters link 102 and prints the following

ONIOM: calculating energy.
 E123=      E_1      E_scf     E_3 (three real numbers)
 ONIOM: extrapolated energy =    (a fourth real number calculated

             				 as, I guess, E_scf - E_1 + E_3) 

	Now my questions: 

i) Is the "oniom extrapolated energy" the valid  energy in an oniom job?
ii) What does E_1 mean?   

	Thanks in advance. I summarize to the list.
	Regards,

						Reinaldo