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AixMarUniv . Campus St. Jérôme
Av. Escadrille Normandie-Niemen
13397 Marseille Cedex 20 - France

Simple HÜckel and LewIS embedded in the Hückel theory

Nicolas Goudard, Yannick Carissan, Denis Hagebaum-Reignier et Stéphane Humbel

Institut des Sciences Moléculaires de Marseille UMR 7313 CNRS
Aix-Marseille Université

Huckel: build + solve the secular determinant.

Obtain molecular orbitals, energy levels, charges density with the simple Hückel method.

Lewis : Resonance & aromaticity

Weights of resonance structures are obtained from either energies differences (HL-CI) or overlaps (HL-P)

Hückel Calculator Version : (Release notes)


Colleages who use HuLiS are invited to contact us and share expertises and practices.

Build a molecule ("Hückel" tools, blue left area)
  • HuLiS is like any other simple Hückel programs with quite a few additionnal features as :
    • - Developped chemical formulae drawing,
    • - Relevant π orbitals drawing,
    • - Adjustable numbering of the atoms,
    • - Adjustable parameters for each bond & atom.*
  • Orbitals are drawn by clicks on the energetic levels.
  • The results button gives access formatted results.

* These can be useful for reparametrization (new atoms, Möebius).

Build resonance structures ("Lewis" tools, orange area).
  • HuLiS contains an automatic Lewis structures' generator, in a single click (no more than a +/- charge).
  • In the expert mode the user can create specific singlet spin coupling.
  • HuLiS will give the weight of each of your structures.
  • You can use the slider on the right to select the N lowest structures.
  • The standalone version, reads/writes gaussian.com files (including NBO-NRT strings).


The program is based on these following references.
Thanks for citing them:


They cite HuLiS : (let us know by sending to Stephane an email if your work does not appear correctly here)
  • in Thiazolo[5,4‐ f ]quinoxalines, Oxazolo[5,4‐ f ]quinoxalines and Pyrazino[ b,e ]isatins: Synthesis from 6‐Aminoquinoxalines and Properties ( Eur. J. Org. Chem. 2021, 2021, 2756 ) by prof F. Mongin et al, Université de Rennes 1: Rennes, Bretagne, France
  • in From Infection Clusters to Metal Clusters: Significance of the Lowest Occupied Molecular Orbital (LOMO) ( ACS Omega 2021, 6, 2, 1339–1351 ) by prof Y. Tsuji et al, Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
  • in Understanding Single-Molecule Parallel Circuits on the Basis of Frontier Orbital Theory ( J. Phys. Chem. C 2020, 124, 5, 3322–3331 ) by prof K. Yoshizawa et al Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
  • in "Resonance Theory Reboot " (ACS JACS 2019)by Eric D. Glendening , Clark R. Landis and Frank Weinhold (Indiana State University and University of Wisconsin - Madison)
  • in "Pyridine vs N-Hydrogenated Pyridine Moieties ... " (ACS Omega 2018)by Dr Chih-Kai Lin et al (National Taiwan University)
  • in "... chromophores: a bottom-up Hückel picture of the excited states of photoactive proteins" (CPPC 2017) by Prof. J. Verlet et al (Durham University)
  • in "Transition-Metal-Free CO-Releasing BODIPY Derivatives ..." (J. Am. Chem. Soc. 2016, 138, 126) by Prof. P. Klán et al (Masaryk University)
  • in "Thermodynamic properties of alkyl 1H-indole carboxylate derivatives ..." (J. Chem. Thermodyn. 2016, 97, 70)" by Prof. Maria D.M.C. Ribeiro da Silva et al. (University of Porto)
  • in several papers like this one, "Unpaired Electrons, Spin Polarization, and Bond Orders in Radicals ..." (Int. J. Quant. Chem. 2014, 114, 696) by Prof. P. Karafiloglou et al (Thessaloniki University)
  • in "Carbo-aromaticity.. (Chem. Soc. Rev. 2015, 44, 6535) and in " ... the ultimate aromatization process" (Tetrahedron 2014, 70, 4957) by Prof. R. Chauvin et al (Toulouse University)
  • in "Correlation between Fourier series expansion and Huckel orbital theory (J. Math. Chem. Soc. 2013, 51, 503) by Prof. Ying Liu et al (Shenyang Normal University)
  • ...

HuLiS is Clean