CCL:G: NBO Natural Bond Orbital Deletion Gaussian 98

[akef afaneh <akef_afnh],[yahoo.com>]

Hi;

I do not know what the purpose of your deletion ($DEL) is, but there are many ways for deletion in Gaussian. First, you must know that this analysis is performed by (1) deleting specified elements (or blocks of elements) from the NBO Fock matrix, (2) diagonalizing this new Fock matrix to obtain a new density matrix, and (3) passing this density matrix to the SCF routines for a single pass through the SCF energy evaluator. The difference between this 'deletion' energy and the original SCF energy provides a useful measure of the energy contribution of the deleted terms.  Now, I can summarize the deletion procedure as follows:

The deletions keylist begins with the "$DEL" keyword. After the last deletion, the word "$END" signals the end of the keylist.

(1) Deletion of entire orbitals.

This is called for by typing "DELETE", then the number of orbitals to be deleted, then the keyword "ORBITAL" (or "ORBITALS"), then the list of the orbitals to be deleted.

Example:

#P RHF/6-31G* Nosymm pop=nbodel opt

H2O

0 1

 8                     0.        0.        0.11469

 1                     0.        0.75408  -0.45874

 1                     0.       -0.75408  -0.45874

 

$NBO file=dfe_c $end

$del

Delete 2 orbitals

6 9

$end

 

(2) Deletion of specific Fock matrix elements.

This is called for by typing "DELETE", then the number of elements to be deleted, then the keyword "ELEMENT" (or "ELEMENTS"), then the list of the elements to be deleted (each as a pair of integers).

Example:

#P RHF/6-31G* Nosymm pop=nbodel opt

CH4

0 1

6                     0.        0.        0.

 1                     0.62565   0.62565   0.62565

 1                    -0.62565  -0.62565   0.62565

 1                    -0.62565   0.62565  -0.62565

 1                     0.62565  -0.62565  -0.62565

 

$NBO file=dfe_c $end

$del

DELETE  3  ELEMENTS 5 16 5 17 5 18

$end

 

(3) Deletion of off-diagonal blocks of the Fock matrix.

Each block is specified by two sets of orbitals, and all Fock matrix elements in common between these two sets are set to zero. This is called for by typing "ZERO", then the number of off-diagonal blocks to be zeroed, and then, for each block, the following:

(1) the dimensions of the block, separated by the word "BY" (e.g., "6 BY 3" if the first set has 6 orbitals and the second set has 3 orbitals);

(2) the list of orbitals in the first set;

(3) the list of orbitals in the second set.

An example is shown below:

$NBO file=dfe_c $end

$del

ZERO  2  BLOCKS  2  BY  5

                               3  4

                               9  10  11  14  19

                      3  BY  2

                               1  2  7

                              20  24

$end

 

This will set the following Fock matrix elements to zero:

(3,9), (3,10), (3,11), (3,14), (3,19), (9,3), (10,3), (11,3), (14,3), (19,3), (4,9), (4,10), (4,11), (4,14), (4,19), (9,4), (10,4), (11,4), (14,4), (19,4), (1,20), (1,24), (2,20), (2,24), (7,20), (7,24) (20,1), (24,1), (20,2), (24,2), (20,7), (24,7)

(4) Deletion of all Rydberg and antibond orbitals.

The Rydberg and antibond orbitals are the non-Lewis NBO orbitals that have stars in their labels (RY*, BD*) in the NBO analysis output. To delete all these orbitals, simply enter "NOSTAR". The result of this deletion is the energy of the idealized NBO natural Lewis structure, with all Lewis NBOs doubly occupied. (Unlike other deletions, in which there is a slight loss of variational self-consistency due to the redistributed occupancy of the deleted orbitals, the result of a "NOSTAR" deletion corresponds rigorously to the variational expectation value of the determinant of doubly occupied Lewis NBOs).

$NBO file=dfe_c $end

$del

      NOSTAR

$end

 

AND SO ON J

 

"etamar:-:fh.huji.ac.il" <owner-chemistry#ccl.net> wrote:

Sent to CCL by: etamar---fh.huji.ac.il
Hi Randall
I dont know what kind of deletion you are interested at, but
you can try this one.
good luck
Tamar

#hf/6-31+g* pop=(full,nbodel) 5d

test

-1 1
cl 0.000000 0.000000 0.000000
c 0.000000 0.000000 2.383179
h -1.061228 0.000000 2.383179
h 0.530614 0.919051 2.383179
h 0.530614 -0.919051 2.383179
cl 0.000000 0.000000 4.766359

$NBO archive file=test $end
$del zero 2 deloc from 1 to 2 from 2 to 1 $END




Quoting "Randall H Goldsmith r-goldsmith _ northwestern.edu"
:

>
> Sent to CCL by: "Randall H Goldsmith" [r-goldsmith^^northwestern.edu]
> Hello all,
>
> I'm looking to perform NBO deletion analysis using the NBO 3.1
> package that comes with Gaussian 98. Following instructions for NBO
> 3.0 implementation in Gaussian 88 (the only ones i can find), i
> attempted to use nonstandard input to tell Gaussian to do the
> analysis, but the job always died prematurely. Does anybody know
> how to perform this analysis in Gaussian 98? Obviously, an example
> job file would be most valuable.
>
> Thank you very much for your time!
>
> randall.
>
>
>
>>
>
>



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