How do I draw an MO diagram?

Type the molecule name (for example O2 or N2), specify the atomic orbitals to use (such as 2s and 2p), and note the total electron count. Figviz arranges the bonding and antibonding MOs by energy, fills the electrons from the bottom up following Aufbau and Hund's rule, and labels the bond order. Refine the prompt if you want specific orbital labels or annotations.

Is the molecular orbital diagram generator free?

Yes. You can generate MO diagrams on the free credits every account starts with. Buying any pay-as-you-go credit pack removes the watermark and unlocks higher resolutions. Credits never expire.

What is the difference between bonding and antibonding orbitals?

Bonding MOs form when atomic orbitals combine in phase. They are lower in energy than the original atomic orbitals and concentrate electron density between the nuclei, stabilizing the bond. Antibonding MOs (marked sigma* or pi*) form when atomic orbitals combine out of phase. They are higher in energy and have a node between the nuclei, which weakens or destabilizes the bond. Net bond order depends on how many electrons occupy each type.

How do I calculate bond order from an MO diagram?

Count the electrons in all bonding MOs, subtract the electrons in all antibonding MOs, then divide by two. Bond Order = (bonding electrons minus antibonding electrons) divided by 2. For O2 there are 8 bonding and 4 antibonding electrons, giving (8 minus 4) divided by 2 = bond order 2, consistent with a double bond.

Can I use the MO diagram generator for chemistry class?

Yes. Download a high-resolution PNG (up to 4K) for slides, lab reports, and printed study guides. As an AI tool it is excellent for practice and teaching; always verify the orbital ordering and electron count against your textbook before submitting high-stakes work. Diagrams from a paid account can be used in your own teaching materials.

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Molecular Orbital Diagram Generator Molecular Orbital Diagrams

Describe any diatomic or small molecule and get a clean, labeled MO diagram in seconds. Bonding and antibonding orbitals, electrons filled in with arrows, energy axis, and bond order, ready for class or lab.

Last updated: 2026-06-21

✓Bonding and antibonding orbitals✓Electron filling with arrows✓Bond order labeled✓Slide and print ready

Molecular Orbital Diagram Generator

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Molecular Orbital Diagram Examples

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MO Diagram of O2

O2 MO diagram with sigma and pi orbitals filled, two unpaired electrons in the degenerate pi* orbitals confirming paramagnetism, and bond order 2 labeled.

O2oxygenparamagnetic

MO Diagram of N2

N2 MO diagram with all bonding MOs filled and no unpaired electrons, giving bond order 3 and diamagnetic character.

N2nitrogentriple bond

MO Diagram of H2

The simplest MO diagram: two 1s atomic orbitals combine to form a sigma bonding MO (filled) and a sigma* antibonding MO (empty), giving bond order 1.

H2hydrogenbond order 1

MO Diagram of F2

F2 MO diagram with 18 electrons filled. Many antibonding orbitals are occupied, resulting in a net bond order of only 1.

F2fluorinebond order 1

Bonding vs Antibonding Orbitals

A conceptual MO diagram illustrating how atomic orbitals combine to form lower-energy bonding MOs and higher-energy antibonding MOs, with the energy axis clearly labeled.

bondingantibondingconceptual

MO Diagram with Bond Order Calculation

An annotated MO diagram showing the full electron configuration with the bond order formula (bonding minus antibonding electrons divided by 2) worked out explicitly beneath the diagram.

bond orderformulaannotated

What is a molecular orbital diagram?

A molecular orbital (MO) diagram is an energy-level chart that shows how atomic orbitals from two or more atoms combine to form new molecular orbitals that belong to the whole molecule. Bonding MOs are lower in energy than the original atomic orbitals and hold the molecule together, while antibonding MOs are higher in energy and weaken the bond. Electrons fill the MOs from the bottom up, following the Aufbau principle and Hund's rule. The resulting electron configuration lets you calculate bond order, predict whether a molecule is diamagnetic or paramagnetic, and understand its reactivity. Figviz generates a clean, labeled MO diagram from a plain description, saving you the time of drawing and placing every orbital by hand.

How to make a molecular orbital diagram

Name the molecule and the atomic orbitals to include (for example, 2s and 2p for second-period diatomics).

Note any special ordering if relevant (for example, for N2, the pi2p orbitals sit below the sigma2p).

Specify the total number of electrons so Figviz fills them in correctly.

Choose a style, aspect ratio, and quality setting, then click Generate.

Read the bond order from the labeled diagram and refine the prompt if any orbital label or electron arrow looks off.

Bonding vs antibonding orbitals and bond order

When two atomic orbitals overlap in phase, they form a bonding MO that is lower in energy and concentrates electron density between the nuclei, which holds the atoms together. When they overlap out of phase, they form an antibonding MO (marked with an asterisk, such as sigma*) that is higher in energy and has a node between the nuclei. Bond order is calculated by subtracting the number of electrons in antibonding MOs from the number in bonding MOs, then dividing by two. A bond order of 1 means a single bond, 2 a double bond, and 3 a triple bond. A bond order of zero means the molecule does not form a stable bond. For example, O2 has bond order 2 and two unpaired electrons in its degenerate pi* orbitals, which explains both its double bond and its paramagnetism.

Tips for an accurate MO diagram

Always state the molecule name and the shell of orbitals to include. For second-period diatomics, deciding whether pi2p sits above or below sigma2p matters: for O2 and F2 the sigma2p is lower, but for N2, C2, and B2 the pi2p levels are lower due to s-p mixing. Provide the total electron count explicitly so the filling is unambiguous. If you want bond order shown, ask for it in the prompt. For teaching diagrams, ask for the energy axis and orbital labels to be clearly visible, and choose 4:3 or 16:9 for slide use.

Frequently asked questions

A molecular orbital diagram generator is a tool that draws a labeled MO energy-level diagram for a molecule. With Figviz you describe the molecule and the orbitals to include, and the AI produces a clean diagram with atomic orbitals on the sides, molecular orbitals in the center, electrons filled as arrows, and bond order labeled, in seconds.

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