GChemPaint/C3/Orbital-Overlap/English

Title of the tutorial: Orbital overlap

Author: Madhuri Ganapathi

Key words: Atomic orbital, Add or modify an atomic orbital tool, rotation and resize of orbitals, positive, negative overlaps and zero overlap, Video tutorial

Visual Cue	Narration
Slide Number 1 Title Slide	Hello everyone. Welcome to this tutorial on Orbital Overlap in GChemPaint.
Slide Number 2 Learning Objectives	In this tutorial, we will learn About different types of orbitals Rotation and resize of orbitals Types of orbital overlaps
Slide Number 3 System Requirement	Here I am using Ubuntu Linux OS version 12.04. GChemPaint version 0.12.10.
Slide Number 4 Pre-requisites	To follow this tutorial, you should be familiar with GChemPaint chemical structure editor. If not, for relevant tutorials, please visit our website.
Switch to GChemPaint application.	I have opened a new GChemPaint application.
Slide Number 5 Atomic Orbital	Let's first see what an atomic orbital is. An atomic orbital is a mathematical function. It describes the wave-like behavior of an electron in an atom. An orbital is a region of space with maximum probability of finding an electron.
Slide Numbers 6 ‘s’ and ‘p’ Orbitals Point to the orbitals	This is an 's' orbital. It has spherical shape. Here are 'p' orbitals in different axes. 'p' orbitals are "dumb-bell" shaped.
‘d’ Orbitals	Next, we have 'd' orbitals in different axes. 'd' orbitals are double "dumb-bell" shaped.
Switch to GChemPaint application.	I have opened a new GChemPaint application.
	Let's first learn about orbitals.
Click on Add or modify an atomic orbital tool	Click on Add or modify an atomic orbital tool.
Point to the properties window.	The Orbital property window opens.
Point to the properties.	This window contains fields like- Coefficient, Rotation and Type.
Point to Type field.	First, I will begin with Type.
Point to 's'	By default, 's' orbital is selected.
Click on p, dxy and dz^2 radio buttons. Point to the orbital shapes.	Let's click on p, d xy and d z square orbital radio buttons. Notice the different orbital shapes displayed alongside.
Point to Coefficient and Rotation	Next let's check the Coefficient and Rotation properties.
Cursor on the value box	Coefficient property has values from -1.00 to 1.00.
Press the down arrow continuously till it reaches 0.6 or so.	Using Coefficient field values, we can vary the size of the orbital. Notice that size of the orbital alongside, has changed.
Cursor on the value box.	Rotation property has values from -180 to 180.
Press the down arrow continuously till it reaches 35 and then press the up arrow continuously till it reaches -35	We can rotate the orbitals clockwise or anticlockwise. Values can be changed using the up and down arrows.
	Let's see how to use orbitals to show different types of positive overlaps.
Slide Number 8 Positive Overlaps	Here is a slide for Positive overlap of different orbitals. 's-s'(ss), 's-p'(sp), 'p-p'(pp) end-on overlaps and 'p-p'(pp) side-wise overlap.
Switch to GChemPaint window.	Let's draw Hydrogen molecule on the Display area.
Press H on the Key board.	Press H on the keyboard.
Set Co-efficient value to 1.	Set Co-efficient value to one.
Click on Add or modify a atom tool. Click on Add or modify a atom tool.
Click Add a bond or change the multiplicity of the existing one tool. Click Add a bond or change the multiplicity of the existing one tool. Ensure that bond length is around 130.
Click on the Display area.	Click on the Display area. Hydrogen molecule is formed.
	Let's start with 's-s'(ss) end-on(endon) overlap.
Click on Add or modify an atomic orbital tool.	Click on Add or modify an atomic orbital tool.
Click on 's' orbital>>click on the Hydrogen atoms of Hydrogen molecule. Point to the s-s end on overlap.	Click on 's' orbital, then click on Hydrogen atoms of Hydrogen molecule. Observe 's-s'(ss) end-on(endon) overlap.
	Now to 'p-p'(pp) end-on(endon) overlap.
Press F on the keyboard	Press F on the keyboard.
Click on Add or modify an atom tool.	Click on Add or modify an atom tool.
Click Add a bond or change the multiplicity of the existing one tool. Point to the molecule.	Click Add a bond or change the multiplicity of the existing one tool. Click on Display area. Fluorine molecule is formed.
Click on Add or modify an atomic orbital tool	Click on Add or modify an atomic orbital tool.
Click on 'p' orbital.	Click on 'p' orbital.
	To form 'p-p'(pp) end-on(endon) overlap, we need 'p' orbitals in horizontal direction.
Click and hold the up arrow triangle	Let's increase the Rotation value to 90. To do this, click and hold the up arrow triangle.
Click on the horizontal p orbital>> Click on Fluorine atom.	Click on horizontal 'p' orbital. Click on one Fluorine atom.
Click on the other Fluorine atom.	Likewise, repeat the process and rotate the 'p' orbital to '-90'(minus90). Click on the other Fluorine atom.
Right click on the orbital>> select Orbital >> click on Properties.	In case you are not able to view the overlap clearly, you can resize the orbital. To do so, we have to change the Coefficient value. Right click on the orbital, select Orbital then click on Properties.
Orbital properties dialogue box opens.	Orbital properties dialog box opens.
Point to 'p-p'(pp) end-on(end on) overlap.	Reduce the Coefficient value till you see a proper overlap. Click on Close and observe the 'p-p'(pp) end-on(end on) overlap.
	Now to 'd-d'(dd) end-on overlap using 'dz^2' orbital.
Press capital F on the keyboard. Point to the list.	Come to the Display Area and press capital F on the keyboard. Select Fe from the list.
Click on Add or modify an atom tool>>Click on the Display area.	Click on Add or modify an atom tool. Click on the Display area.
Click on Add a bond or change the multiplicity of the existing one tool>>Click on Display area.	Click on Add a bond or change the multiplicity of the existing one tool. Click on iron atom(Fe) to draw a bond.
Click on Add or modify an atomic orbital tool>>Select dz^2 orbital.	Click on Add or modify an atomic orbital tool. Select 'dz^2' orbital radio button.
Point to the arrow triangles.	Rotate the 'dz^2' orbital to horizontal direction. Also, for proper overlap, decrease the Coefficient value to around 0.8 or so.
Click on the bonded iron atoms to overlap dz^2 orbitals.	Click on the bonded Iron atoms to overlap "dz^2" orbitals.
	Now let's learn about side-wise overlap of 'p' orbitals. Ensure that current element is Carbon.
Click on Add a bond or change the multiplicity of the existing one tool.	Click on Add a bond or change the multiplicity of the existing one tool. Ensure Bond length is close to 90 and click on the Display area.
Click on Add or modify an atomic orbital tool.	Click on Add or modify an atomic orbital tool.
Click on 'p' orbital radio button>> Click on the edges of the bonds. Point to the overlap.	Click on 'p' orbital radio button.	Rotate the orbital to vertical position if it is in horizontal position. Click on the edges of the bonds. In this type of overlap, lobes are of same sign. Observe the 'p-p' side-wise overlap.
	Next, we will move to negative and zero overlaps.
Slide Number 9 Negative overlaps	Here is a slide with different types of negative overlaps.
	Now, I will demonstrate how to draw a negative overlap.
Switch to GChemPaint window.	I have opened a new GChempaint window.
Click on Add a bond and change the multiplicity of the existing tool >>Click on the Display area.	Click on Add a bond and change the multiplicity of the existing tool. Click on the Display area.
Click on Add or modify an atomic orbital tool.	Click on Add or modify an atomic orbital tool.
Click on the p orbital radio button >>click on one edge of the bond.	Click on 'p' orbital radio button then click on one edge of the bond.
Cursor on Rotation arrow triangle.	Rotate 'p' orbital to 180 degree to flip it upside down.
Click on the other edge of the bond. Point to the overlap.	Click on the other edge of the bond and observe the negative overlap. In this type of overlap, lobes of orbitals are of opposite sign.
	Now, let's learn how to create a zero overlap.
Slide Number 10 Zero Overlap	Here is a slide for zero overlap.
Click on Add a bond and change the multiplicity of the existing tool>> Click on the Display area.	Click on Add a bond and change the multiplicity of the existing tool. Click on the Display area.
Click on Add or modify an atomic orbital tool.	Click on Add or modify an atomic orbital tool.
Click on Add or modify an atomic orbital tool.	Click on Add or modify an atomic orbital tool.
Click on the 'p' orbital radio button>> click on one edge of the bond.	Click on 'p' orbital radio button and then click on one edge of the bond. Ensure that 'p' orbital is vertical.
Click on the 's' orbital radio button >>click on one edge of the bond.	Click on 's' orbital radio button and then click on other edge of the bond.
Point to the overlap	Observe zero overlap. In this overlap, orientation of the orbitals is not same.
	Let's summarize what we have learnt.
Slide Number 11 Summary	In this tutorial we have learnt , About different types of orbitals End-on(endon) and side-wise(sidewise) overlaps Rotation and resize of orbitals Positive, negative and zero overlap.
Slide Number 12 Assignment	Here is an assignment. Draw 's-p' end-on overlap with Hydrogen chloride(H-Cl) molecule Draw side-wise overlap of 'dxy-dxy' orbitals Draw other negative and zero overlaps. Hint: Rotate the orbitals for proper overlap. Your completed assignment should look like this.
Slide Number 13 Acknowledgement	Watch the video available at this link. http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarizes the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it
Slide Number 14	The Spoken Tutorial Project Team: Conducts workshops using spoken tutorials Gives certificates to those who pass an on-line test For more details, please write to contact@spoken-tutorial.org
Slide number 15	Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at this link http://spoken-tutorial.org/NMEICT-Intro
	Drawings are contributed by Arathi This is Madhuri Ganapathi from IIT Bombay signing off. Thank you for joining.

Contributors and Content Editors

Madhurig, PoojaMoolya