PA3 File Extension

Have a problem opening a .PA3 file? We collect information about file formats and can explain what PA3 files are. Additionally we recommend software suitable for opening or converting such files.

What is the .PA3 file type?

The .pa3 file extension primarily denotes the Parity Volume Set (Parchive, parity archive) file format widely used in Usenet. Created from one or several original files, such parity files are fixers used to verify the integrity of the original files and restore lost or damaged data if necessary. There are three versions of the Parchive format: Version 1 (.par), Version 2 (.par2), and Version 3 (.par3) developed by Yutaka Sawada.

Parity .pa3 files are actually .par3 files, their file extension was shortened to adhere to the 8.3 filename convention requiring three-character extensions. Basically, a .pa3 file is a small index file saved using the third version of the Parchive format. Contrary to traditional backup files, PA3 files do not contain any actual data, just file hashes necessary for file verification and repair purposes. Unfortunately, with the development of new data transfer technologies, the Parchive format has become nearly obsolete, but it is still possible to open some .pa3 files using the MultiPar tool.

In addition, the .pa3 file extension is also associated with StabCal (Stability Calculation for Aqueous Systems), a thermodynamic equilibrium modeling application developed by Dr. Hsin-Hsiung Huang from Montana Tech of the University of Montana. The software uses the .pa3 extension and other similar alphanumeric extensions (.pa2, .pa4, etc.) to denote files storing data necessary for calculations of thermodynamic properties, such as Helgeson-Kirkham-Flowers models. With StabCal installed, such .pa3 files can be opened with a double click.

Moreover, the .pa3 file extension is also used by Program PRESENCE, a Windows-based occupancy modeling software tool designed to estimate the probability of detecting a target species on a specific site. Each analysis is stored as a project that includes several files: an input data file (.pao), a project results file (.pa3), and an output file (.out). Thus, a PA3 file is a summary results file storing data about all models that meet the specified requirements.

Plus, the .pa3 file extension's association also belongs to QuickWave (QW), an advanced electromagnetic simulation software package from Poland-based developers QWED. In this case, .pa3 files are intermediate parameter files created in QW-Editor using the desired parameters specified by the user to be transferred to QW-Simulator to conducts calculations.

Software to open or convert PA3 files

You can open PA3 files with the following programs:
QuickPar by Peter B. Clements
MultiPar by Yutaka Sawada

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