Subject: One-electron Integral (core hamiltonian)

From: "Iraj Daizadeh" <[email-masked]>
Date: Fri, 20 Mar 1998 16:05:59 -0800

Hello.

(As you are well aware, I am slowly but surely dissecting my way through G94
code.) My problem is this:

I have written a line or two in my link that prints out the so-called core
hamiltonian (1 electron integral) as follows:

C
      Call FileIO(2,-IRwH,NTT,V,0)
      do 214 i=1,NTT
        If(Abs(V(i)).lt.Thresh) V(i) = Zero
214     write (IH,2010) V(i)
C

Here, IRwH is set to 515, and thresh = 1e-6.

The results for H2 (Hf/sto-2g) at 8 ang. separation is:

   -0.528103461738361310000000000000E+00
    0.000000000000000000000000000000E+00
   -0.512985653829729940000000000000E+00

In G94 standard output file, the core hamiltonian has the values:

 ****** Core Hamiltonian ******
             1             2
   1 -0.520545D+00
   2  0.000000D+00 -0.520545D+00

It seems that G94 takes the average of the matrix elements in the one-electron
hamiltonian.  Is this true and if so why?

Thank you in advance.

Iraj.

-- 
Iraj Daizadeh
Department of Chemistry
University of California
One Shields Ave.
Davis, CA  95616-5295
Phone:  530.754.8695
Fax:    530.752.8995
email:  [email-masked]