Particularly in the determination of LUMO HOMO for dyes or similar products.
The HOMO level of the dyes can be estimated from their oxidation potential by using cyclic voltammetry.
You can deduce LUMO level from the HOMO and optical band gap.
Optical bandgap=(ELUMO-EHOMO)
1.Targema, M., Obi-Egbedi, N. O. & Adeoye, M. D. Molecular structure and solvent effects on the dipole moments and polarizabilities of some aniline derivatives. Computational and Theoretical Chemistry 1012, 47–53 (2013).
2.Li, Y. et al. Electrochemical properties of luminescent polymers and polymer light-emitting electrochemical cells. Synthetic Metals 99, 243–248 (1999).
3.Hou, J. et al. Synthesis of a Low Band Gap Polymer and Its Application in Highly Efficient Polymer Solar Cells. J. Am. Chem. Soc. 131, 15586–15587 (2009).
I also would be interested in obtaining some software for such calculations. I know that there are plenty of apps like these (just read - http://en.wikipedia.org/wiki/List_of_quantum_chemistry_and_solid-state_physics_software ) but most of them need really complex knowledge about the quantum chemistry or similar stuff.
Almost every software that does "quantum chemical" computation can be used to estimate HOMO / LUMO numbers. Check OrbiMol -- they may already have your molecule in their database. Among others, I prefer to use GAMESS (PC), free and relatively easy to use. But not free of perils -- you have to extremely sure about geometry optimization, (I know there are experts of this field lurking in RG -- hope they answer!) -- once geometry is fixed, you can probably do a single point SCF energy calculation. In the output file you will find the homo lumo energies. More complex systems needs more attention (DFT) though -- keep in mind that these packages run with the assumption that the molecule in question is neutral and at its ground state. Once an electron is removed from the HOMO or added to the LUMO coulombic
interactions would change the energy levels, and this interaction is not
taken into effect. Also check out quantum espresso, Q-Chem (the beta was free, but not the current commercial release), VASP. I am sure others will suggest more.
Dear Palash Gangopadhyay
By using Wien2k program, is it possible to determine these energy levels: LUMO, HOMO.
I agree with Palash - be careful, however, not to use these software packages as a "black box"; if you put garbage in, you get garbage out as well.
Provided that you know what you're doing: I could recommend the ADF code - simple to use, versatile, and many tutorials are available.
@Kebbab, I have not seen your response earlier -- sorry to get back to you after so long -- Unfortunately I have not used Wien2k myself, so I will not be of much help.
Dear Palash Gangopadhyay
thank you very much for your response, excuse me if I have created for you any inconvenience
I have been using ORCA, which works great for molecules although I hear you can use it for crystalline structures with more coding on your part. It is quick and can be used in most platforms. Unfortunately I don't think it can be run parallel for anything that is not a Linux machine (any windows 7 machine will only run the calcs on one core from what I can tell). -Nathan
- Badges
- Science topic