Subject: Summary: Fock and other hamiltonian matrices in G94

From: Sergei Tretiak <[email-masked]>
Date: Mon, 12 Feb 1996 13:05:47 -0500 (EST)

Dear Netters,

Here is the summary of the messages I got in response to my previous
message about printing of hamiltonian matrices from G94.  
Many thanks to everybody who kindly replied my query.
		
		Sincerely,
				Sergei Tretiak

*********************** my first message *************************
 
How to print: 

1.Fock matrix F (Probably the easiest way is to use NBO 
block: $NBO keywords FAO, FNAO, .....) 

2.Core-Hamiltonian h(1). (Can be printed by using IOP(3/33=1-5) to print 
one and two electron integrals) 

3.An effective one-electron potential-the Hartree-Fock potential v(1).
Presumably F=h(1)+v(1).  

************************* summary of replies************************
 
1.  IOp33(5=3) (equivalently, IOp(5/33=3) turns on print during the
    SCF, including Fock matrices among other things.  It's a bit
    verbose since these are printed every iteration, so if your case
    is big, you might want to converge the SCF first and then do
    Guess=Read with the print turned on so you only get print for 1
    cycle.  

2.  IOp33(3=1) should get you the core hamiltonian.  

3.  V = F- H isn't printed as such but you can get it by
    subtraction.  If you want to read back the printed matrices,
    routine LTRead in util.a reads in a lower triangular matrix in the
    format in which Gaussian prints it.  
 
					Mike Frisch

---------------------------------------------------------------------

1.  You can use the NBO pacakge to print these. Use POP=NBOREAD and then
supply the NBO keywords at the end of the input. 

2.  The one electron integrals are printed this way IOP(3/33=1) To get the
two electron integrals you need IOP(3/33=6) and ExtraLinks=L316. You
should also add NoRaff so that the integrals are not summed into
Raffenetti contractions. 

3.  I am not sure what you want here. The formulas for producing the Fock
matrix are well known if you have the integrals and the indices as
produced by the above but is that what you are trying to produce? 

  Douglas J. Fox
  Director of Technical Support
  [email-masked]

------------------------------------------------------------------------

***********************my second message ************************* 
1.I want to print two electon matrices from G94. I use following input: 

# GEOM=CHECKPOINT GUESS=CHECKPOINT TEST HF DIRECT STO-3G 
#p POP=NBORead iop(3/33=6) ExtraLinks=L316 NoRaff
 
but I get an error message: 
 ...   *** Dumping Two-Electron integrals *** 
ISMode= 0 Mode=1 IBase= 1 IBasD= 1 262145 
 DBase= 0 DBasD= 0 0 IReset= 2 262139 
IntCnt= 0 ITotal= 0 NWIIB= 262144 ISym2E=1 
 Illegal range for read: IUnit= 10 Address= 0 Length= 131072 File length= 
 \ 0.  
 Error termination in NtrErr:  
 NtrErr called from NtrIO.  
Segmentation fault - core dumped 
 What is wrong?
  
2.Can I print all (1,2) integrals to FORTRAN readable files? 

************************* reply ************************

1. The problem is that DIRECT says not to write out the integrals, so
   there aren't any on the disk for L316 to print out.  In G94, just
   leave out DIRECT.  In G94, where Direct is the default, you need to
   say SCF=Conventional to tell it to write the integrals. 

2. There's no built-in way to write out the integrals to a fortran
   unformatted file, so you have three choices, all of which are   
   relatively easy:

   a.  Follow the example in the manual (which is similar to link 317)
       which shows how to make your own link which processes
   b.  Modify link 316 to write the integrals out unformatted as it
       prints them. 
   c.  Make link (or modify an existing link) which can run in-core,
       using a call to FoFDir to load the integrals in canonical order. 
       You can find a sample call in routine UHFOpn in link 502. 

				Mike Frisch