if i want add initial guess into input how can I do it? what is the initial guess?
Dear Fatemeh,
The keyword Guess = Cards is for reordering. An example for the use of this keyword is as follows:
Reading in Orbitals with Guess=Cards. Some or all of the orbitals may be replaced, after the initial guess is generated, usingGuess=Cards. Here is some sample input for this option, which replaces orbitals 1 and 4 (note that the format for the third and following lines is specified in line 1):
(3E20.8)
1
0.5809834509E+00 0.4612416518E+00 -0.6437319952E-04
0.1724432549E-02 0.1282235396E-14 0.5417658499E-13
0.1639966912E-02 -0.9146282229E-15 -0.6407549694E-13
-0.4538843604E-03 0.6038992958E-04 -0.1131035485E-03
0.6038992969E-04 -0.1131035471E-03
4
0.7700779642E-13 0.1240395916E-12 -0.3110890228E-12
-0.4479190461E-12 -0.1478805861E-13 0.5807753928E+00
0.6441113412E-12 -0.3119296374E-14 0.1554735923E+00
-0.1190754528E-11 0.2567325943E+00 0.1459733219E+00
-0.2567325943E+00 -0.1459733219E+00
0
An orbital number of zero ends the replacement orbital input
For more on this topic, please use the following link:
http://www.gaussian.com/g_tech/g_ur/k_guess.htm
Hoping this will be helpful,
Rafik
thanks a lot Mr Karaman. but i don't know how can define this orbitals?
actually I use AOMix program to get stric energy, so i have to use an output of gaussian with this keyword.
I appreciate if you guide me.
Dear Fatemeh,
Using AOMix program,
Energy decomposition analysis (EDA)
AOMix can be used for energy decomposition analysis (EDA) of Morokuma and
Ziegler.65,66 Note that this AOMix functionality has been tested for only closed-shell systems using all electron basis sets. In EDA, one can define the following contributions to the electronic interaction energy between two fragments in a molecule: electrostatic energy EES, exchange repulsion energy (Pauli repulsion) EEX, and orbital interaction energy Eorb :
E int = EES + EEX + Eorb .
The electrostatic energy and exchange repulsion energy can be combined together into a single term, Esteric . As a result,
E int = Esteric + Eorb
AOMix allows to evaluate Esteric and Eorb , using Gaussian calculations. In order to proceed with such calculations, a user has to setup a new Gaussian calculation using the converged wavefunctions of two fragments (see Appendix II). After the corresponding GUESS=CARDS
input file is prepared by AOMix with the FO execution option, a Gaussian calculation of the whole complex using this input file will have to be executed. The orbital interaction term Eorb is be readily extracted from the electronic energy values in the 1st and the last SCF cycles:
Eorb = E (last. SCF) - (E 1st. SCF)
For example, for the interaction between the BH3 and NH3 fragments in the BH3NH3 adduct, AOMix-FO reports:
For more, please see pages 37-40 in the publication contained in the following link:
http://www.sg-chem.net/aomix/AOMix-manual.pdf
Hoping this will be helpful,
Rafik
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