Subject: Calculation of the FC contributions

From: "Carol Y.Y. Au" <[email-masked]>
Date: Thu, 6 May 1999 03:19:07 -0700 (PDT)

Dear CCLers,

	I have some questions in the calculations of the Fermi Contact 
contribution.

	Referring to the Gaussian menu, the FIELD keyword requests that a 
finite field be added to calculation. When the field involve a Fermi 
contact term,

	FIELD=F(M)N

where F(M) designates a Fermi contact perturbation for atom M (following
the ordering in the molecule specification sectin of the input file). 
N*0.0001 specifies the magnitude of the Fermi contact perturbation.

	For instance, Field=F(3)27 which applies a perturbation of 0.0027 
times the spin density on atom 3. I have no idea in choosing the value of N. 
I am uncertain whether this value is arbitrary or have some rules in 
choosing it. 

	Could anyone give me some suggestions in choosing the value of N?

	Thanks.

Best wishes,

Carol Au
Dept. of Chem. CUHK
E-mail :[email-masked]
Phone  :(852) 2609 6167
Fax    :(852) 2603 5057