{"id":27942155,"url":"https://github.com/pranabdas/orientx","last_synced_at":"2026-01-22T05:33:09.347Z","repository":{"id":116040037,"uuid":"403659813","full_name":"pranabdas/orientx","owner":"pranabdas","description":"Laue diffraction simulation using OrientExpress","archived":false,"fork":false,"pushed_at":"2021-09-06T14:52:44.000Z","size":3237,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-05-07T11:34:28.712Z","etag":null,"topics":["crystallography","diffraction","laue"],"latest_commit_sha":null,"homepage":"https://pranabdas.github.io/research/orient-express/","language":null,"has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/pranabdas.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2021-09-06T14:49:18.000Z","updated_at":"2025-04-10T05:29:29.000Z","dependencies_parsed_at":"2023-03-17T18:30:53.628Z","dependency_job_id":null,"html_url":"https://github.com/pranabdas/orientx","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/pranabdas/orientx","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/pranabdas%2Forientx","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/pranabdas%2Forientx/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/pranabdas%2Forientx/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/pranabdas%2Forientx/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/pranabdas","download_url":"https://codeload.github.com/pranabdas/orientx/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/pranabdas%2Forientx/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":28656281,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-01-22T01:17:37.254Z","status":"online","status_checked_at":"2026-01-22T02:00:07.137Z","response_time":144,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["crystallography","diffraction","laue"],"created_at":"2025-05-07T11:26:37.944Z","updated_at":"2026-01-22T05:33:09.342Z","avatar_url":"https://github.com/pranabdas.png","language":null,"readme":"# Laue diffraction simulation using OrientExpress\n\nLaue diffraction is a method to find the crystallographic direction of single\ncrystals. We shine the single crystal with white x-ray (having a continuous\nrange of wavelength), and record the diffracted pattern on a x-ray film or image\nplate. Analyzing the pattern, we learn about the crystal structure. Sometimes we\nneed to compare the observed pattern with a simulated pattern to identify a\ncrystallographic plane. Here is how we can simulate the Laue pattern of a single\ncrystal. This tutorial is meant for the first-time users.\n\n- Download OrientExpress [here](\nhttp://ccp14.cryst.bbk.ac.uk/ccp/web-mirrors/lmgp-laugier-bochu/orientex.zip)\nand unzip in a Windows computer. Click **OrientExpress.exe** to launch the\nprogram. Below is the Main Window you will see once you launch OrientExpress.\n\n![screenshot-01](./assets/oe-01.png)\n\n- To simulate Laue pattern of a single crystal, we need to insert the required\nparameter in OrientExpess. We can choose to insert the parameter manually. Go to\nmenu bar Data \u003e\u003e Keyboard. You will see following window:\n\n![screenshot-02](./assets/oe-02.png)\n\n- Let’s simulate Laue pattern for IrO\u003csub\u003e2\u003c/sub\u003e single crystal (right now I\nhave the parameter for this compound, but you can try with any other compound).\nIrO\u003csub\u003e2\u003c/sub\u003e has tetragonal crystal structure, note the respective parameters\nin the following window:\n\n![screenshot-03](./assets/oe-03.png)\n\n- Here a, b, c are lattice constants. α, β, γ are angles between principle axes.\nGroup is space group of the crystal structure. Dist.(Cm) is the distance between\nsingle crystal surface and Laue recording x-ray film or image plate. Angle(°)\ndepends on the geometry of the Laue setup. In case of metals (like in our\nexample IrO\u003csub\u003e2\u003c/sub\u003e), we record the back-scattered x-ray pattern. In this\ncase Angle 180°. In some cases of transparent single crystals, we record the\ntransmitted pattern, in that case, Angle = 0°. λ1 and λ2 are lower and upper\nlimit of x-ray source we are using for the experiment. Height and Width\ncorresponds the height and width of the x-ray recording film or the dimensions\nof Image plate.\n\n- You can save these data in a `.dat` file for future use. Just click the Save\nbutton on the top right of Data input window.\n\n- Next time, if you like to load this saved data, choose File from Data menu,\nand navigate to the data file.\n\n- Now we are ready to simulate the Laue pattern. First let’s see the Laue\npattern for [100] crystallographic direction.\n\n- Go to Matrix \u003e\u003e Acquisition in the menu bar. You will see following window:\n\n![screenshot-04](./assets/oe-04.png)\n\n- Here we need to insert the crystallographic directions of our crystal we want\nto simulate. Here is an example:\n\n![screenshot-05](./assets/oe-05.png)\n\n- Please select Récipr. (stands for reciprocal space). Click OK, and here it is.\n\n![screenshot-06](./assets/oe-06.png)\n\n\n- Congratulations! Now you know how to simulate Laue pattern of any single\ncrystal with known lattice parameters. Very simple, isn’t it? Now I will\ndescribe couple of useful techniques which you may find useful.\n\n- Rotating the pattern to see the changes. Go to Simulation \u003e\u003e Laue in the menu\nbar.\n\n![screenshot-07](./assets/oe-07.png)\n\n- Now you can put degree of rotation with respect to rotation axes and click\nDraw. That’s it.\n\n- Another feature maybe be very useful: superimposing a simulated patter over\nthe experimental pattern.\n\n- Please save your experimental Laue pattern in .jpg (or another supported\nformat). Note: sometimes I noticed that high resolution images show some scaling\nproblem, in that case please scale down the resolution. The image file I am\nusing is 625 pixels by 500 pixels.\n\n- Go to menu bar: Coordinates \u003e\u003e Image and browse your image file.\n\n![screenshot-08](./assets/oe-08.png)\n\n- Next we need to set the scale. Go to Scale \u003e\u003e Measure, then I click at two\npoints on the horizontal axis and enter the horizontal dimension of my image\nplate.\n\n- Then we need to set the Origin, Go to Origin \u003e\u003e Point, and click in the center\nof the film/pattern.\n\n![screenshot-09](./assets/oe-09.png)\n\n- In the main window, you should see something like this:\n\n![screenshot-10](./assets/oe-10.png)\n\n- That’s all from me. Now you may want to explore further yourself. Happy\nlearning!\n","funding_links":[],"categories":[],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fpranabdas%2Forientx","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fpranabdas%2Forientx","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fpranabdas%2Forientx/lists"}