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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: poonilization on May 04, 2015, 07:36:15 AM

Title: Electronic Spectroscopy of Diatomic Molecules Question
Post by: poonilization on May 04, 2015, 07:36:15 AM

Hello, i've just attempted a past paper exam question and was wondering if someone would be kind enough to check through my answer and see if i have answered it correctly. Question: http://i.gyazo.com/f3f7872e167b583a99d30b9402dbc820.png

My answer: http://i.gyazo.com/49079f0efe28c52d11e230e20b724d7a.jpg

So for part i) i've worked out ωe'-2ωeXe'= 1718.8 cm^-1
                                            ωe'-4ωeXe'= 1657.6 cm^-1
then solve the simultaneous equation and got ωeXe' = 30.6 cm^-1 and ωe = 1780 cm^-1

did the same to calculate ωe'' and ωeXe''

and for part ii) i just calculated the difference between the (0,2) and (0,1) transition which is 1264.1, and then just added that onto 41638.5 to calculate the (0,0) transition.

Title: Re: Electronic Spectroscopy of Diatomic Molecules Question
Post by: mjc123 on May 05, 2015, 10:33:12 AM

Part i) looks correct. Part ii) is wrong - you're assuming that the difference between columns 0 and 1 is the same as between columns 1 and 2, which it is not - the anharmonicity correction changes, as you correctly realised in calculating the answers to part i). Were you just applying a formula without understanding it?