Molecular graphics

Scientists use pictures to see tiny things.

These tiny things are called molecules. They are too small to see with eyes. Pictures help us see how they work.

Long ago, people drew these tiny bits by hand. Later, they made models out of hard wood. These models used colors to show different parts. For example, red shows oxygen.

Now, we use computers to make pictures. Some pictures look like balls and sticks. Other pictures show how much space they take up. We can even use 3D glasses to see them. This makes the tiny parts look real. It is a great way to study science.

Scientists use pictures to study molecules. Molecules are tiny parts of our world. They are too small to see with our eyes.

Long ago, people drew these shapes by hand. Later, they made models from hard wood. These models used colors to show different atoms. This is called the CPK coloring scheme. In this system, carbon is black and oxygen is red.

Today, we use computers to make these pictures. One way is the ball-and-stick model. It uses small spheres for atoms. It uses rods for the bonds that hold them together. Another way is the space-filling model. This shows how much space each atom takes up.

Some pictures even look 3D. You can use special glasses to see them. Some glasses are active. They use batteries to change the lenses. Other glasses are passive. They are less expensive and very common now.

These tools help us see how the tiny parts of our world work.

Molecular graphics is a special way to study tiny molecules. These molecules are the building blocks of our world. Because they are too small to see, scientists use pictures to understand them.

These pictures help show the properties of different molecules. Experts use these visual tools to see how atoms fit together. It is a very important way to do science today.

There are different ways to draw these tiny shapes. One way is the ball-and-stick model. It uses small spheres for atoms and rods for the bonds.

Another way is the space-filling model. This shows the actual space each atom takes up. You can even see the charge of a molecule using a surface model.

These different views help scientists see different details.

Long ago, people did not have computers for this work. Robert Corey and Linus Pauling made models from hard wood. They used a scale where 1 inch equaled 1 angstrom.

They also created the CPK coloring scheme. This system uses colors to tell atoms apart. For example, carbon is black and oxygen is red. W.L. Koltun improved these models in 1966.

Computers changed how we see molecules in the 1960s. Project MAC made the first wire-frame models on a screen.

In 1965, Carroll Johnson shared the ORTEP plot. This showed molecules as balls and sticks with shapes called ellipsoids. These ellipsoids show how atoms move. In 1966, Cyrus Levinthal and Robert Langridge showed the first protein on a screen. They used a protein called myoglobin for this task.

Many scientists use 3D graphics to see depth. Some people use active 3D glasses that need batteries.

These glasses use special ceramics to change the lenses. Other people use passive 3D glasses. These are cheaper and very common now. Using these tools makes the tiny world feel real. It helps us see how big molecules like hemagglutinin work.

Molecular graphics is the scientific discipline of studying molecules through graphical representations. It involves a specific philosophy of using visual tools to understand molecular properties. According to IUPAC, these representations must be shown on a "graphical display device." Because molecules are far too small to see with the naked eye, these graphics are essential. They allow scientists to visualize how atoms are arranged and how they interact.

There are several distinct ways to represent these structures. The ball-and-stick model uses small spheres to represent atoms. It uses rods to represent the chemical bonds connecting them.

Another method is the space-filling model. This model draws atoms as solid spheres to suggest the actual space they occupy. This is based on their van der Waals radii, which is the distance where atoms begin to interact. In these models, atoms that share a bond will overlap.

Scientists also use surface models to show electrostatic potential. These surfaces use colors to show charge density. For example, red areas indicate a net positive charge density. Blue areas indicate a net negative charge density.

Before computers, scientists used physical models to study molecular structures. Robert Corey and Linus Pauling developed a system using hard wood. They worked at a scale where 1 inch represented 1 angstrom. They used a clamping device to keep the molecular configuration steady. These pioneers also established the CPK coloring scheme. This scheme helps scientists differentiate atom types using color. In this system, carbon is black, oxygen is red, and nitrogen is blue. W.L. Koltun improved these models in 1966, and they are now called Corey-Pauling-Koltun (CPK) models.

Digital molecular graphics began to emerge in the mid-1960s. Project MAC produced the first wire-frame models on a cathode ray tube. In 1965, Carroll Johnson distributed the Oak Ridge thermal ellipsoid plot, or ORTEP. This visualized molecules as ball-and-stick models. It used lines for bonds and ellipsoids to represent the probability of thermal motion. ORTEP became the standard for displaying X-ray crystallography data. In 1966, Cyrus Levinthal and Robert Langridge achieved a milestone. They used a wireframe representation to display the protein myoglobin.

To see depth, researchers often use 3D graphics technology. During the 1970s, scientists developed methods to display 3D graphics on cathode ray tubes. They used continuous tone computer graphics with electro-optic shutter viewing devices. One type is an active shutter 3D system. These systems generate different perspective views for the left and right eye. These active glasses require batteries to work. They use lead lanthanum zirconate titanate (PLZT) ceramics as electronically controlled shutters.

Many modern systems use passive, polarized 3D glasses. These are less expensive and rely on the wearer's own perception to see 3D effects.

As molecules grew larger, traditional physical model-building could not scale. This drove the need for advanced macromolecular crystallography tools. In 1975, Marge Legg solved a high-resolution structure of staph nuclease using the FIT program. In 1976, Jim Hogle solved the structure of monoclinic lysozyme. Alwyn Jones later developed the FRODO program. This program allowed scientists to overlay molecular electron density with a hypothetical structure. These digital tools replaced the physical Richards' Box for modeling density in 3D.

Molecular graphics connects chemistry to computer science and physics. The field has moved from hand-drawn sketches to high-performance rendering. Nelson Max contributed to this by creating realistic renderings of macromolecules. These renderings use reflecting spheres to improve visual accuracy. Today, the field includes various software platforms. These range from early systems like RasMol to modern browser-based tools. These tools allow scientists to explore the complex shapes of the microscopic world.