Homework Help Question & Answers

# 7) The Intensity of a transition, I, from the initial state with wavefunction w.) to a...

The intensity of a transitlon, I, from the initial state with wavefunction $$\psi_{2}(\ddot)$$ to a final state, $$\psi_{b}(\vec{r})$$ is given by:

$$\left.I=\int \psi_{b}^{*}(-) \cdot \hat{\alpha}_{r}\right) \psi_{2}(\vec{r}) d r$$

where $$\vec{d}_{r}^{-}$$) is the transition operator (e.g. the dipole moment operator, $$\hat{\mu}(-)$$, for an infrared absorption transition and the polarisability operator, $$\hat{\alpha}(\vec{r})$$, for a Raman transition). For the integral (and thus intensity) to be non-zero, explain what is required in terms of symmetry.

#### Homework Answers

✔ Recommended Answer
Answer #1

#### Sign Up to Unlock the answer FREE

Already have an account? Log in

Initial and final state wavefunctions should have opposite parity i.e opposite symmetry. If one is odd, the other must be even to make any transition possible between these two states. Parity of a wavefunction is determined using the angular momentum quantum number 'L' of the wavefunction. If 'L' is odd 1,3,5..., then wavefunctions have odd parity and if 'L' is even 2,4,6..., then wavefunctions have even symmetry.

Add a comment
Know the answer?
Your Answer:

#### Post as a guest

Your Name:

What's your source?

#### Earn Coin

Coins can be redeemed for fabulous gifts.

Similar Homework Help Questions
ADVERTISEMENT
Free Homework Help App

Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?

Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
Active Questions
ADVERTISEMENT