CASTEP file format description

Many people share .castep files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .castep file can be edited, converted or printed with. On this page, we try to provide assistance for handling .castep files.

1 filename extension(s) found in our database.

.castep - CASTEP Data

The CASTEP data files are related to CASTEP. The CASTEP file is a CASTEP Data. CASTEP is a full-featured materials modelling code based on a first-principles quantum mechanical description of electrons and nuclei. It uses the robust methods of a plane-wave basis set and pseudopotentials.

Data files
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CASTEP Data related extensions:
CASTEP Cell Input Data
CASTEP Check Binary
CASTEP Geometry Data
CASTEP Parameters Data

Naturally, other applications may also use the .castep file extension. Even harmful programs can create .castep files. Be especially cautious with .castep files coming from an unknown source!

Can't open a .castep file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

Operating systems currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

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If you have useful information about the .castep file format, then write to us! >> CASTEP file