parameter for Extended Huckel Theory

[broadcome]

Dear all,

I want to modify EHT parameter to get more accurate result.
But, paramters make me confusing.
In short, is 'ionization_potential' in ATK parameter is 'onsite energy' of EHT?




* reference parameter: E_onsite, ζ1, c1, ζ2, c2 (On site energy, exponents, coefficients) for each orbital.
* ATK parameter:  ionization_potential, wolfsberg_helmholtz_constant, onsite_hartree_shift, vcuum_level, principal_quantum_number, angular_momentum, slater_coefficients, weights  

I think exponents ζ =  slater_coefficients, coefficients c = weights
and then... What is 'E_onsite'?

The name 'onsite_hartree_shift' is similar. but it's only for elements, not orbitals.
May be, ionization_potential is onsite energy.
But I'm not sure. Am I right?


Thanks,

[kstokbro]

You interpretation is correct. I would also like to refer to the manual
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/chap.atkse.html
In table 1 and 2 we relate the keywords to the symbols, and the definition of the method is written in this chapter. Let me know if this makes it clearer.


In 11.2 the U (onsite_hartree_shift) is defined per atom. In 11.8 we will have new parameter sets, where we calculate U per orbital. In 11.8 we also provide parameters for spin polarized calculations. 11.8 also supports SlaterKoster parameters,  and you can use DFTB parameters, Vogl's parameters, etc.
We will include some parameters with the distribution, but it is very easy to use your own parameter sets.

We expect 11.8 to be available as an alfa version next week.

[broadcome]

Thank you for your help~