What is MIME type "chemical/x-gaussian-cube"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

chemical/x-gaussian-cube is the MIME type for files that store volumetric chemical data. They hold grid-based information for properties like electron density and molecular orbitals.

These files use the CUB extension. The format is text-based. It includes headers with grid dimensions, atomic coordinates, and numerical data arrays.

Used to visualize 3D molecular structures.
Helps in analyzing chemical simulations.
Supports computational studies in chemistry research.

The format is common with Gaussian software and is also supported by other molecular modeling tools. For a deeper dive into Gaussian Cube files, visit Gaussian.

Associated file extensions

.cub

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: chemical/x-gaussian-cube

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="chemical/x-gaussian-cube">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'chemical/x-gaussian-cube');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.cub

FAQs

What is the chemical/x-gaussian-cube MIME type used for?

This MIME type is used to identify Gaussian Cube files, which contain volumetric data for computational chemistry. These files, typically ending in .cub or .cube, store grid-based data such as electron density and molecular orbitals generated by software like Gaussian.

How do I configure Apache to serve .cub files?

To ensure your Apache server sends the correct headers, add the following line to your .htaccess file or main configuration: AddType chemical/x-gaussian-cube .cub .cube. This helps client applications recognize the file as chemical data rather than plain text.

Can web browsers display chemical/x-gaussian-cube files natively?

No, standard browsers like Chrome and Firefox cannot render 3D volumetric chemical data natively. To display these files on a website, you need to use JavaScript libraries such as JSmol, NGL Viewer, or 3Dmol.js that can parse and render the format within an HTML canvas.

Which software applications open files with this MIME type?

Files served as chemical/x-gaussian-cube are widely supported by molecular visualization tools. Common applications include VMD (Visual Molecular Dynamics), PyMOL, UCSF Chimera, and Avogadro. Since the format is text-based, they can also be opened in standard text editors.

How do I set up Nginx to handle Gaussian Cube files?

In Nginx, open your mime.types file (usually located in /etc/nginx/) and add the entry: chemical/x-gaussian-cube cub cube;. If you cannot edit the global file, you can add types { chemical/x-gaussian-cube cub cube; } inside your specific server or location block.

Is the Gaussian Cube format text or binary?

The format is text-based (ASCII). It contains a header defining the grid dimensions followed by atomic coordinates and scalar values. Because these files can be large, it is highly recommended to enable GZIP compression on your server for this MIME type to speed up transmission.

What does the 'x-' prefix indicate in this MIME type?

The x- prefix stands for "experimental" or "extension," indicating that chemical/x-gaussian-cube is a non-standard subtype not officially registered in the IANA standards tree. However, it is the accepted convention for serving Cube files in the scientific community.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.