GChemPaint/C3/Orbital-Overlap/English-timed

Time	Narration
00:00	Hello everyone.Welcome to this tutorial on Orbital Overlap in GChemPaint.
00:06	In this tutorial, we will learn-
00:08	About different types of orbitals
00:11	Rotation and resize of orbitals
00:14	Types of orbital overlaps.
00:17	Here I am using Ubuntu Linux OS version 12.04,
00:21	GChemPaint version 0.12.10.
00:26	To follow this tutorial, you should be familiar with
00:31	GChemPaint chemical structure editor.
00:34	If not, for relevant tutorials, please visit our website.
00:38	Let us first see what an atomic orbital is.
00:42	An atomic orbital is a mathematical function.
00:46	It describes the wave-like behavior of an electron in an atom.
00:52	An orbital is a region of space with maximum probability of finding an electron.
00:58	This is an 's' orbital.
01:00	It has spherical shape.
01:03	Here are 'p' orbitals in different axes.
01:06	'p' orbitals are "dumb-bell" shaped.
01:09	Next, we have 'd' orbitals in different axes.
01:13	'd' orbitals are double "dumb-bell" shaped.
01:17	I have opened a new GChemPaint application.
01:20	Let us first learn about orbitals.
01:24	Click on Add or modify an atomic orbital tool.
01:28	Orbital property window opens.
01:30	This window contains fields like- Coefficient, Rotation and Type.
01:36	First, I will begin with Type.
01:40	By default, 's' orbital is selected.
01:42	Let us click on p, d xy and d z square orbital radio buttons.
01:50	Notice the different orbital shapes displayed alongside.
01:54	Next let us check the Coefficient and Rotation properties.
01:59	Coefficient property has values from -1.00 to 1.00.
02:04	Using Coefficient field values, we can vary the size of the orbital.
02:10	Notice that the size of the orbital alongside, has changed.
02:15	Rotation property has values from -180(minus) to 180.
02:20	We can rotate the orbitals clockwise or anticlockwise.
02:25	Values can be changed by using the up or down arrows.
02:30	Let us see how to use orbitals to show different types of Positive overlaps.
02:36	Here is a slide for Positive overlap of different orbitals.
02:40	's-s'overlap, 's-p'overlap, 'p-p'overlap and 'p-p' side-wise overlap.
02:51	Let us draw Hydrogen molecule on the Display area.
02:55	Press H on the keyboard.
02:58	Set the Co-efficient value to one.
03:01	Click on Add or modify an atom tool.
03:04	Click Add a bond tool.
03:07	Ensure that bond length is around 130.
03:11	Click on the Display area.
03:14	Hydrogen molecule is formed.
03:17	Let's start with 's-s' end-on overlap.
03:20	Click on Add or modify an atomic orbital tool.
03:24	Click on 's' orbital.
03:28	Then click on Hydrogen atoms of Hydrogen molecule.
03:33	Observe 's-s' end-on overlap.
03:35	Now to 'p-p' end-on overlap.
03:38	Press F on the keyboard.
03:42	Click on Add or modify an atom tool.
03:45	Click Add a bond tool.
03:49	Ensure that bond length is around 200.
03:53	Click on the Display area.
03:56	Fluorine molecule is formed.
03:59	Click on Add or modify an atomic orbital tool.
04:02	Click on the 'p' orbital.
04:05	To form 'p-p' end-on overlap, we need 'p' orbitals in horizontal direction.
04:11	Let us increase the Rotation value to 90.
04:15	Click on the 'p' orbital.
04:18	Click on one Fluorine atom.
04:21	Likewise, repeat the process and rotate the 'p' orbital to '-90'(minus90).
04:27	Click on the other Fluorine atom.
04:30	In case you are not able to view the orbital clearly, you can resize the orbital.
04:36	To do so, we have to change the Coefficient value.
04:40	Right click on the orbital, select Orbital then click on Properties.
04:46	Orbital properties dialog box opens.
04:50	Reduce the Coefficient value till you see a proper overlap.
04:54	Click on Close button.
04:57	I will repeat the process for the other orbital.
05:01	Observe 'p-p' end-on overlap.
05:04	Now to 'd-d' end-on overlap using 'dz^2' orbital.
05:09	Come to the Display Area and press capital F on the keyboard.
05:14	Select Fe from the list.
05:17	Click on Add or modify an atom tool.
05:20	Click on the Display area.
05:23	Click on Add a bond tool.
05:26	Click on iron atom(Fe) to draw a bond.
05:29	Click on Add or modify an atomic orbital tool.
05:32	Select 'dz^2' orbital radio button.
05:37	For proper overlap, decrease the Coefficient value to 0.8.
05:42	Click on the bonded Iron atoms to overlap "dz^2" orbitals.
05:49	Observe 'd-d' end-on overlap.
05:52	Now let's learn about side-wise overlap of 'p' orbitals.
05:57	Ensure that current element is Carbon.
06:02	Click on Add a bond tool.
06:05	Ensure Bond length is around 90.
06:08	Click on the Display area.
06:12	Click on Add or modify an atomic orbital tool.
06:16	Increase the Coefficient value to one.
06:20	Click on 'p' orbital radio button.
06:23	Rotate the 'p' orbital to vertical position if it is in horizontal position.
06:29	Click on the edges of the bonds.
06:32	Observe the 'p-p' side-wise overlap.
06:37	In this type of overlap, lobes of orbitals are of same sign.
06:43	Next, we will move to negative and zero overlaps.
06:46	Here is a slide for negative overlaps.
06:51	I have opened a new GChempaint application.
06:55	Now, I will demonstrate how to draw a negative overlap.
06:59	Click on Add a bond tool.
07:02	Ensure that Bond length is around 90.
07:05	Click on the Display area.
07:08	Click on Add or modify an atomic orbital tool.
07:12	Click on 'p' orbital radio button then click on one edge of the bond.
07:17	Rotate the 'p' orbital to 180 degree to flip it upside down.
07:23	Then click other edge of the bond.
07:27	Observe negative overlap.
07:29	In this type of overlap, lobes of orbitals are of opposite sign.
07:34	Now, let's learn how to create a zero overlap.
07:38	Here is a slide for zero overlap.
07:42	Click on Add a bond tool.
07:45	Click on the Display area.
07:48	Click on Add or modify an atomic orbital tool.
07:52	Click on the 'p' orbital.
07:54	Rotate the 'p' orbital to original position.
07:59	Click on one edge of the bond.
08:02	Click on 's' orbital
08:05	and then click on other edge of the bond.
08:09	Observe zero overlap.
08:12	In this type of overlap, orientation of the orbitals is not same.
08:17	Let us summarize what we have learnt.
08:20	In this tutorial we have learnt, * About different types of orbitals
08:24	End-on and side-wise overlaps
08:27	Rotation and resize of orbitals
08:30	Positive, negative and zero overlap.
08:34	Here is an assignment.
08:36	Draw 's-p' end-on overlap with Hydrogen chloride(H-Cl) molecule
08:40	Draw side-wise overlap of 'dxy-dxy' orbitals
08:44	Draw other negative and zero overlaps.
08:48	Hint: Rotate and resize the orbitals for proper overlap.
08:56	Your completed assignment should look like this.
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09:43	Drawings are contributed by Arathi.
09:45	This is Madhuri Ganapathi from IIT Bombay signing off. Thank you for joining.

Contributors and Content Editors

Gaurav, PoojaMoolya, Pratik kamble, Sandhya.np14