Sudip1993

Hello, this is my talk page. You can discuss anything (most preferably regarding physics, while complying with the terms and conditions) here. If you have any specific questions related to any of the wiki-pages that I have edited, it will be better to ask them in their respective talk pages. I am going to work on Symmetry of diatomic molecules. There is no separate wikipedia page on it, so I am going to create one. My plan about the page is as following:

• I will start with an introduction, I will give a brief overview of why we want to look into molecular symmetry (because it gives us insights about the properties such as structure and spectra without doing the actual rigorous calculation).
• This will be followed by a section on how symmetry is related to group theory and the idea of point groups.
• Then I will state and describe the 5 kinds of geometrical symmetries (symmetry axis, plane of symmetry, inversion center, rotation-reflection axis, identity) and the corresponding operations (I will also introduce Schoenflies notation).

• Then I will enlist the different kinds of point groups associated with molecular symmetry. I specific, I will discuss in detail the most prominent symmetry groups in diatomic molecules, namely C_∞v(linear) and D_∞h(linear with inversion center). In case of a Homonuclear diatomic molecule, we see both the symmetries and in case of Heteronuclear diatomic molecule, we see only the former one.
• Then I am planning to give a brief description of group representation and irreps (I am not sure about whether this will be relevant for my current reading or not, so there is a possibility that I will not include it).
• Then I would like to include a section on how the symmetry and the corresponding commuting operators differ in diatomic molecules from the atomic case. Here, Hamiltonian does not commute with L² and thus 'l' is no longer a good quantum number. The CSCO in this case is {H, J_z,L_z,S²,S_z,A, Π} (A inverts only one of the spatial co-ordinates).
• Then I would like to discuss about the most general Hamiltonian of a diatomic molecule and Born-Oppenheimer approximation and the 'electronic ket' (or electronic wave function, or the word 'electronic term' used by Landau-Lifshitz).
• Then I would like to probe into the role of symmetry in this electronic structure, and would introduce the molecular term symbol and discuss about Λ-doubling, gerade and ungerade states.
• Now I would like to explore the observable consequence of symmetry in physical observations, i. e., the difference in spectral lines of homonuclear and heteronuclear molecules.

Here, I would like to state the selection rules for the purely vibrational, purely rotational and vibration-rotation (or vibronic) transition for the two kinds of diatomic molecules. It will turn out that in order to show a purely vibrational spectrum, a diatomic molecule must have dipole moment that varies with distance. So, homonuclear molecules don't undergo electric dipole vibrational transitions; it shows, however, vibronic transition spectrum. A heteronuclear molecule shows both the spectra, although it needs to abide by the corresponding selection rules. It turns out that both the vibrational and rotational quantum numbers must change in the transition. So, the so called 'Q' (Δv=(+/-)1, ΔJ=0) branch of rotational spectra is forbidden.

• In the last section, I will discuss the intersection of potential curves for a diatomic molecules and the role of symmetry in it. Here, I would also like to discuss the von Neumann- Wigner non-crossing rule.

- This is my detailed plan till now. It can change depending on my further studies and discussions. --Sudip1993 (talk) 11:05, 9^th October 2014 (UTC), 2014.

Welcome!

Some cookies to welcome you!

Welcome to Wikipedia, Sudip1993! Thank you for your contributions. I am VQuakr and I have been editing Wikipedia for some time, so if you have any questions feel free to leave me a message on my talk page. You can also check out Wikipedia:Questions or type {{help me}} at the bottom of this page. Here are some pages that you might find helpful:

• Introduction
• The five pillars of Wikipedia
• How to edit a page
• Help pages
• How to write a great article
• Discover what's going on in the Wikimedia community

Also, when you post on talk pages you should sign your name using four tildes (~~~~); that will automatically produce your username and the date. I hope you enjoy editing here and being a Wikipedian! VQuakr (talk) 02:55, 15 October 2014 (UTC)

Thank You!

Thank you,VQuakr, for your suggestions and the gift! It was sweet indeed! The links you sent were of immense help for me in getting started. I look forward to more suggestions and co-operations from you in future also. It is a privilege to meet you. :) --Sudip1993 (talk) 17:44, 15 October 2014 (UTC)

License tagging for File:Images elements.png

Thanks for uploading File:Images elements.png. You don't seem to have indicated the license status of the image. Wikipedia uses a set of image copyright tags to indicate this information.

To add a tag to the image, select the appropriate tag from this list, click on this link, then click "Edit this page" and add the tag to the image's description. If there doesn't seem to be a suitable tag, the image is probably not appropriate for use on Wikipedia. For help in choosing the correct tag, or for any other questions, leave a message on Wikipedia:Media copyright questions. Thank you for your cooperation. --ImageTaggingBot (talk) 19:05, 26 October 2014 (UTC)

Image

Thank you for pointing it out. There seemed to be an issue with the license, which was not included in the categories listed in the link given. So, I have deleted the respective image from the wikipedia page.--Sudip1993 (talk) 19:32, 26 October 2014 (UTC)

A barnstar for you!

	The Rosetta Barnstar
	Nice topic for a Wikipedia page. Subhadip Roy (talk) 17:28, 14 November 2014 (UTC)

File source and copyright licensing problem with File:Co-ordinate system for a diatomic molecule.png

File Copyright problem

Thanks for uploading File:Co-ordinate system for a diatomic molecule.png. However, it currently is missing information on its copyright status and its source. Wikipedia takes copyright very seriously.

If you did not create this work entirely yourself, you will need to specify the owner of the copyright. If you obtained it from a website, please add a link to the page from which it was taken, together with a brief restatement of the website's terms of use of its content. If the original copyright holder is a party unaffiliated with the website, that author should also be credited. You will also need to state under what licensing terms it was released. Please refer to the image use policy to learn what files you can or cannot upload on Wikipedia. The page on copyright tags may help you to find the correct tag to use for your file.

Please add this information by editing the image description page. If the necessary information is not added within the next days, the image will be deleted. If the file is already gone, you can still make a request for undeletion and ask for a chance to fix the problem.

Please also check any other files you may have uploaded to make sure they are correctly tagged. Here is a list of your uploads. If you have any questions please ask them at the Media copyright questions page. Thank you. Sfan00 IMG (talk) 09:26, 15 November 2014 (UTC)

Problems with upload of File:Two possible initial states of the system.png

Thanks for uploading File:Two possible initial states of the system.png. You don't seem to have said where the image came from, who created it, or what the copyright status is. We require this information to verify that the image is legally usable on Wikipedia, and because most image licenses require giving credit to the image's creator.

To add this information, click on this link, then click the "Edit" tab at the top of the page and add the information to the image's description. If you need help, post your question on Wikipedia:Media copyright questions.

For more information on using images, see the following pages:

• Wikipedia:Image use policy
• Wikipedia:Image copyright tags

Thank you for your cooperation. --ImageTaggingBot (talk) 00:06, 24 November 2014 (UTC)