Miramodus

Molecular models, crystal structure models and mineral structures

We design, build and sell beautiful premium quality ball and stick molecular models and crystal structure models for teaching, museum displays, presentations, awards, legal cases - or for anyone who just wants a stunning scientific model.

Molecular Models are a fascinating and engaging part of chemistry teaching, and are a useful tool for explaining chemical concepts or material properties to colleagues and customers.  They provide a tangible interactive means for educators to demonstrate the relation between molecular structure and chemical function in a form that cannot be replicated with, for example, computer imaging. Similarly, they usefully illustrate the relation between mineral structures and physical or chemical properties. Alternatively, they can simply be works of art - three dimensional sculptures that enrich a work or visitor area. Whatever you need them for, our models are accurate, look stunning, and will enhance any office or laboratory.

 

Crystal structure model of diopside mineral

Molecular and crystal structure Models

Standard 1cm=1Å scale

                   

A girl sitting with a giant molecular model on a grass lawn

Large and Giant models

 

Examples of the models we build can be seen throughout our website. Please use the links above to find out more about our products, search our model catalogue, or to inquire about having us design and build a model of your structure.

We hope you enjoy looking round our website and seeing the quality, and variety, of stunning scientific models that we make for display and education. To buy models from us, or to discuss what you would like made, please either complete the order form or the contact form, or email us at sales@miramodus.com

 

molecular models of primitive unit cells with acrylic lattice planes

 

Pre-constructed Models

Pre-constructed models represent the vast majority of our sales, and they are some of the finest crystal structure models that can be purchased.  We have the widest range of scales of crystal structure models in the world, ranging from a scale of 1cm=1Å (“Beevers’ Models”™) through to our giant molecular models at a scale of 20cm=1Å or greater, and in a huge range of materials.  Almost all of our models are made to order, with the exception of a small number of the commonest chemical structures that we keep in stock, and nothing is 'standard' about them. If a bond angle in a "tetrahedrally" coordinated atom in the structure is 112°, the balls are drilled with holes arranged at that angle - we don't insist that you have to compromise by using regular tetrahedral coordination. The fact that we work with that accuracy can make all the difference between representing features that exist in a crystal and missing them out entirely. What's more, because our models are all made to scale, you also get to see the relative sizes of crystal structures - with regular model kits, for example, a diamond unit cell is much larger than that of sodium chloride, whereas in reality (and in our models) the opposite is true.

Beevers Models (named after their creator, Arnold Beevers) are made with acrylic balls and steel rods, but we also work with a wide range of materials to suit your purpose and your budget. We have made and sold molecular and crystal structure models in acrylic, phenolic resin, wood, brass, copper, aluminium, silver and a host of other materials.

Gallium nitride model made with brass and aluminium balls

A model of Gallium Nitride made with brass and aluminium balls, linked by green anodised aluminium rods on a granite base.


The accuracy and compactness of our Beevers Models™ system allows our model range to extend over the entire spectrum of 3-dimensional structures in Chemistry, Biology, Geology, Physics and Mathematics.  Our huge list of Beevers' ball and stick models for sale from our catalogue includes crystal structure models, biological, physical, mathematical and crystallographic teaching models. We also make an extensive range of models of organic and inorganic molecules - or any compound you want to order.  All the usual favourites are available - you can buy a molecular model of DNA or of RNA, inorganic molecules such as fullerenes (buckyballs), from C28 through C60 and C70 to C720 and beyond, inorganic structures such as NaCl or YBCO, and innumerable materials you have probably never encountered, such as Thorium Zinc Carbide. Even if the material that you want is not in our catalogue - or you want a molecular model of an entirely new compound - we will still be able to make your structure, whatever its size; all we need are the crystallographic details or node coordinates.

 

Multiple bonds in our models 

All of our larger scale models (including our giant molecular models) can be made with double bonds, triple bonds or quadruple bonds as part of the structure. We have never attempted quintuple or sextuple bonds and, given their extreme rarity, we don't anticipate ever needing to, but we could include them in larger models if it were ever necessary. Similarly, we can include multiple bonds in allenes and similar structures. How the rods are arranged in triple and quadruple bonds is generally at the customer's discretion, but our default design is to have the bonds symmetrically arranged around the bond axis, rather than to have the rods in a line. So, a triple bond cut across its axis would have three rods at the corners of an equilateral triangle rather than looking like a double bond with an extra bond added in the middle. A quadruple bond would be arranged with either four bonds in square, or a central bond and three surrounding bonds in an equilateral triangle.

Because of size constraints, we do not currently make Beevers models with multiple bonds, but we are hoping to be able to introduce these with new equipment later in 2020 - where necessary, we currently indicate double bonds in Beevers models by using thicker (2mm diameter) rods, in either aluminium, copper or brass, depending on the customer's preference.

 

Scale matters!

All our models are made accurately and to scale, making it possible to directly measure angles and lengths, to visualise the relative scale of different structures and to show how, for example, a solvent molecule can enter into a porous structure. With other standard model systems, this simply isn't a reliable option, as the user has no assurance that the solvent and the matrix have been made on the same scale. With our models you can immediately see, for example, why diamond is more dense than graphite and why zeolites absorb some compounds but not others.

 

Kits

Model kits for any of our models can be supplied on request. Because it is largely impractical to send our large models and giant models out as fully constructed molecules or crystals, we routinely supply these models as kits, albeit kits made specifically for the construction of a particular molecule or crystal. If you want a more general kit of large or giant atoms and bonds, we are more than happy to make those up for you, and you can buy exactly what you want as we sell the atoms and bonds individually. Giant kits are fantastic for teaching, for interactive museum exhibits, and for fun activities.

That being said, we don't generally advise people to buy Beevers models in kit or self-build form. Because Beevers models are largely designed for display or teaching specific crystallographic or structural concepts, they are not designed to be taken apart and rebuilt, and they are not as easy to construct as normal model kits. By their nature, our Beevers models don’t readily lend themselves to being sold as kits but we are prepared to sell them for self-build. The buyer needs to be aware, and accept, that they are not as easy assemble as most people expect.

 

 

 

What do you want from your molecular model?

Before we build a model of a crystal structure or a molecule, we need to decide on its purpose. Any worthwhile model has a purpose, but we need to remember that the purpose of a molecular model is not to be a facsimile of the real thing - the real thing is a diffuse quantum cloud of electrons held in check by ridiculously small nuclei composed of protons and neutrons. - in which case the purpose must be in representation of specific aspects of the structure.
 

There are a number of different types of molecular model, and each can be used to illustrate different aspects of the molecules that they represent, but there are two fundamental things that they show: either the position of the nuclei and the connections between them, or the volume occupied by the electrons. The former are typically represented by ball and rod structures or framework models, and allow visualisation of the atom positions in relation to one another and whether or not there are bonds between them. Space-filling models, on the other hand, allow visualisation of the volume occupied by the molecules (but bear in mind that molecules comprising diffuse electron clouds don’t have hard boundaries). There are other specialist forms, of course, such as polyhedral structure models, that are used to illustrate the coordination polyhedra around cations.


Most of us start learning about molecular structures in school. We are taught that we can draw structures comprising element symbols that we join together with lines and, later, that we can combine some groups in units, such as -CH3. At this stage of a science student’s education, space-filling models have tremendous value, as they usefully show how the simple 'structures’ that are written on paper actually represent voluminous electron clouds that are held in position by the nuclei. Or we can just tell school students that the clouds have these shapes and they should accept that (for now…).  As the shape and geometry of electron orbitals and chemical bonds become more familiar to the students, the size and shape of the electron clouds become less significant in the chemistry that we teach. The shapes and sizes of the electron clouds, and hence the shapes of the molecules themselves, become implicit in the written chemical structure. Few of us give a second thought to this process, but when you draw a divalent oxygen, don't you just know there are two non-bonding electron pairs sitting there, too? Most of the time it's enough to represent the relative positions of the nuclei. In the same way that a paleozoologist can look at a skeleton of an extinct animal and visualise the muscles of the living creature, how it held itself and how it moved, skilled and experienced chemists can automatically visualise the electron clouds for themselves.  This is incredibly useful and central to the utility of ball and stick models – we can, without expending much conscious thought, extrapolate the three-dimensional electron clouds in a molecule from the positions of the nuclei. This means that we can learn far more from these ‘skeletal’ structure models than might appear to be the case.  
All this explains why ‘ball and stick’ models can be so useful in science teaching, and why they remain the most common form of molecular model. Chemical function is determined by shape and form just as much as it is by other physical attributes such as charge separation - and, because the user can see right through a ball and rod structure to atoms on the other side of the model, the model’s teaching potential is enhanced. The user is able to clearly see the nature and type of atoms that make up the structure through the whole structure, along with the the manner in which the atoms are joined together to form the shapes that those linkages produce. If we represent the structure with space-filling models, we would normally be unable to see beyond the outermost layer of atoms. Being able to look through the structure and into its interior allows huge amounts of structural information to be conveyed in a simple, elegant and efficient form.


Our models

This is where Miramodus come in. In previous times, many chemists made their own models - but that was in an age when research worked more slowly, academic pressures were lower and people had far more time to spend making the models. Besides, many of the models that people made probably weren't actually that well made - consider for a moment how few have survived. Our role, then, is to make those models for businesses, museums, academics, individuals, lawyers, artists - anyone who wants a fine-looking model.

Ours is a business that was started by Arnold Beevers, an early crystallographer, who started the business as a unit around forty years ago within the University of Edinburgh. After Arnold's death and some uncertainty about its future, we separated from the university and 'Beevers Models’ became a private concern - the alternative was that it would have simply ceased to exist, which would have been a tragedy - Beevers models are found in museums, universities and businesses around the world. We employed new staff, and a few years ago, we moved out and are now based in the Scottish Borders, completely separate from the university.

Our business focuses on ball and spoke models of inorganic structures and small organic molecules. We now build giant molecular models, metal molecular models, Perspex molecular models, 3d printed models, medium scale model kits, and any new challenges that customers like to throw at us.