GChemPaint/C3/Orbital-Overlap/English-timed

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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