DOI Number : 10.5614/itbj.sci.2012.44.2.1
Hits : 5

Ab initio calculation of UV-absorption spectra of chlorophyll a: Comparison study between RHF/CIS, TDDFT, and semi-empirical methods

Veinardi Suendo1,3,* & Sparisoma Viridi2

1Inorganic and Physical Chemistry Research Division, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung,
Jalan Ganesha 10, Bandung 40132, Jawa Barat, Indonesia
2Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung,
Jalan Ganesha 10, Bandung 40132, Jawa Barat, Indonesia
3National Center for Nanotechnology, Jalan Ganesha 10, Bandung 40132,
Jawa Barat, Indonesia

Email : vsuendo@chem.itb.ac.id


Abstract. Chlorophyll a is one the most abundant pigment on Earth that responsible for trapping the light energy to perform photosynthesis in green plants. This molecule has been studied for many years from different point of views in both experimental and theoretical interests. In this study, the restricted Hartree-Fock configuration interaction single (RHF/CIS), time-dependent density functional theory (TDDFT) and several semi-empirical methods (CNDO/s and ZINDO) calculations were carried out to reconstruct the UV-Vis absorption spectra of chlorophyll a. In some extend, the calculation results based on single molecule approach were succeeded to reconstruct the absorption spectra but required to be rescaled to fit the experimental one. In general, the semi-empirical methods provide better energy scaling factor that closer to unity. However, they lack of vertical transition fine features with respect to the spectrum obtained experimentally. Here, the ab initio calculations provide more complete features, especially the TDDFT at high level of basis sets that also has a good accuracy in the transition energies. The contribution of ground states and excited states orbitals in the main vertical transitions is discussed based on delocalization nature of the wavefunctions and the presence of solvent through polarizable continuum model (PCM).

Keywords: Chlorophyll a; CIS; CNDO/S; Electronic transition; TDDFT; UV-Vis

Download Article
 
Bahasa Indonesia | English
 
 
 

Notification:

Begin on 10 October 2014 this website is no longer activated for article process in Journal of Mathematical and Fundamental Sciences, Journal of Engineering and Technological Sciences, Journal of ICT Research and Applications and Journal of Visual Art and Design. The next process will be proceeded under new website at http://journals.itb.ac.id.

For detail information please contact us to: journal@lppm.itb.ac.id.

 
       
       
       ITB Journal Visitor Number #10040121       
       Jl. Tamansari 64, Bandung 40116, Indonesia Visitor IP Address #       
       Tel : +62-22-250 1759 ext. 121 2011 Institut Teknologi Bandung       
       Fax : +62-22-250 4010, +62-22-251 1215 XHTML + CSS + RSS       
       E-mail : journal@lppm.itb.ac.id or proceedings@lppm.itb.ac.id Developed by AVE