---
title: "GSAS-II"
url: "https://help.dectris.cloud/en/article/gsas-ii"
language: "en"
last_updated: "2026-07-16T01:09:02.653Z"
---

# GSAS-II

## **Introduction**

The [GSAS-II environment](https://app.dectris.cloud/sections/library/environments/public?id=0197380f-19ae-7910-88c1-ed2755101f66) contains the full GSAS-II graphical suite pre-installed on an Ubuntu desktop. Use it to:

-   Import and visualise X-ray or neutron powder / single-crystal diffraction patterns
-   Perform Rietveld refinement, Pawley fits, PDF analysis, texture, size–strain and more
-   Plot difference curves, reciprocal-space maps and peak statistics.

## **Environment configuration**

### **Installation directories**

-   GSAS-II is installed in `/home/cloud/gsas2full`.
-   Python dependencies are installed in the `base` Conda environment. This can be activated from the terminal using the command:

```plaintext
conda activate base
```

### **Usage example**

Launch GSAS-II by clicking on the icon in the Ubuntu application launcher:

![](https://cdn-assets.productfruits.com/762f8435-47f9-43ae-a05a-d335560fb45f)

It is also possible to launch the program from the terminal, using the following command:

```plaintext
/home/cloud/gsas2full/RunGSASII.sh
```

## **Version history**

### **Version 0**

-   Initial installation of GSAS-II (Binary version 5805, v5.2.0)

### **Version 1**

-   Updated GSAS-II (1a0aee, 22-Apr-2025 20:33. Tag: #5806)
-   Installation directory has been changed from `/home/cloud/g2main` to `/home/cloud/gsas2full`.

## **References**

1.  GSAS-II page: [https://advancedphotonsource.github.io/GSAS-II-tutorials/](https://advancedphotonsource.github.io/GSAS-II-tutorials/)
2.  GSAS-II open source license: [https://raw.githubusercontent.com/AdvancedPhotonSource/GSAS-II/master/LICENSE](https://raw.githubusercontent.com/AdvancedPhotonSource/GSAS-II/master/LICENSE)
3.  Citation: Toby, B. H., & Von Dreele, R. B. (2013). “GSAS-II: the genesis of a modern open-source all purpose crystallography software package”. Journal of Applied Crystallography, 46(2), 544-549. doi:10.1107/S0021889813003531