Sains Malaysiana 43(4)(2014): 637–642

Determination of Potential Curves of Br₂ in Franck-Condon's Region

(Penentuan Potensi Lengkung Br₂ di Rantau Franck-Condon)

EDO S. JANIC¹, VLADIMIR BUTIGAN¹, JASMINA DJ. NOVAKOVIC²* & MILENA LEKIC¹

¹Faculty of Physics, University of Belgrade, Studentski trg, 11000 Belgrade, Serbia

²Graduate School of Computer Sciences, Megatrend University, Bulevar Umetnosti 29

11000 Belgrade, Serbia

Received: 7 May 2012/Accepted: 7 August 2013

ABSTRACT

The extinction of Br₂ molecules in gas state is measured for different wavelengths of incident light in interval of 370 – 570 nm by method of gas spectroscopy. The measurement is made on the basis of Franck-Condon's principle, under which a transition to a more excited state is done without changing the intercore distance (in further text, R). The graph of energy dependence on extinction is drawn. On the graph are recognized two Gausses slopes and their separation (deconvolution) is done. The complete Gausses functions are determined on graph. The method of mirror symmetry is applied on Gausses slopes of extinction and symmetrical extinction values (Es) are obtained. Borders of Franck-Condon’s area are determined from ground state of Linear Harmonic Oscillator (LHO). Tables of dependence on R and the excitation energy are given. On the basis of these tables are drawn potential curves of electron energy E(R) in excited electronic states of Br₂ molecules as functions of R in Franck-Condon's area.

Keywords: Br₂; extinction; Franck-Condon's region; intercore distance; potential curve

ABSTRAK

Kepunahan molekul Br₂ dalam keadaan gas diukur dengan jarak gelombang yang berbeza cahaya tuju dalam tempoh daripada 370-570 nm dengan menggunakan kaedah gas spektroskopi. Pengukuran ini dibuat berdasarkan prinsip Franck-Condon dengan peralihan kepada keadaan teruja dilakukan tanpa menukar jarak antara teras (dalam teks seterusnya, R). Graf tenaga pergantungan kepada kepunahan dilukis. Di dalam graf tersebut, dua cerun Gausses dan pemisahan mereka (deconvolution) dilakukan. Fungsi Gausses yang lengkap ditentukan pada graf. Kaedah cermin simetri digunakan pada cerun Gausses kepunahan dan nilai kepunahan simetri (Es) diperoleh. Kawasan sempadan Franck-Condon ditentukan daripada keadaan asas daripada Pengayun Harmonik Linear (LHO). Jadual pergantungan R dan tenaga pengujaan diberi. Berdasarkan jadual ini, lengkung potensi tenaga elektron E(R) akan dilukis dalam keadaan elektronik teruja molekul Br₂ sebagai fungsi R di kawasan Franck-Condon.

Kata kunci: Br₂; jarak antara teras; kepunahan; potensi lengkung; rantau Franck-Condon

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*Corresponding author; email: jnovakovic@megatrend.edu.rs