You can use standard tools like the 7-Zip Official Site to extract the contents.
Downloading unknown file types, especially in compressed formats, carries inherent risks.
E7V File Extension: What Is It & How To Open It? - Solvusoft
If you are downloading these files as a .zip archive, you are receiving a compressed "container" that bundles one or more .e7v files into a single, smaller package.
Some versions are used by electronic structure software to store data on 3-dimensional grids.
There are no widely known general-purpose programs that open these files. Opening them typically requires the original software that created them or a Hex editor for manual data inspection. Working with Zipped e7v Files
They may represent highly specific, compressed wavelet files or proprietary application data.
Bundling these files into a ZIP archive makes them easier to transfer over the internet and reduces the storage space they occupy. Security and Safety Warnings