Simple HÜckel and LewIS embedded in the Hückel theory

Obtain orbitals with the simple Hückel method + resonance energy, aromaticity
Additionnaly, the weights of a mesomeric scheme can be obtained
from either energies differences (HL-CI) or overlaps (HL-P)

April 2012: a PhD position is available in HuLiS development team.
Please contact Denis as soon as possible, and before may 15th 2012.

Hückel Calculator

1. Build your molecule (in the simple Hückel framework, "Hückel" tools, blue left area)
   • At this point, HuLiS behave like other simple Hückel programs with quite a few additionnal features such as :
     • Developped chemical formulae drawing (with explicited hydrogens),
     • Relevant π orbitals drawing,
     • Adjustable numbering of the atoms,
     • Adjustable parameters bond per bond (off diagonal terms) and atom per atom (diagonal terms of the hamiltonian). These can be usefull for reparameterization for new atoms or Möebius-like systems.
   • Orbital drawing is obtained by clicking the energetic levels.
   • The results button gives access .. to the full results (text format).
2. Build all the mesomeric structures you are interested in ("Lewis" tools, orange right area).
   • Per default the simple HL-CI scheme is applied
   • The more elaborated HL-P scheme is selected through the option menu
   • HuLiS will give some idea about the weight of each of your structures.
   • You can use the slider on the right to select the N lowest structures.

Ressources

The standalone Java Web Start version of HuLiS will run until december 31th, 2014 Double-click on the downloaded file to run the application and accept the certificate because the applet requires the system clipboard. You can copy the downloaded JNLP file on your desktop.
Mini manuel en Français acknowledgments to Benoit Braïda (Jussieu), and Paul Fleurat-Lessard (Lyon) for their careful reading/suggestions.
Online tutorial in english (html)
The page related teaching materials around HuLiS page. (html)
Online Molecular orbitals for 3D systems : OrbiMol (html)

Java related informations

To use HuLiS, the minimum version 1.5 of JAVA must be installed on your computer. You can check your JAVA version typing "java -version" in a command prompt window. You can downlad the latest version of JAVA here.
You can see release notes here for more informations about HuLiS versions.

References