---
tags: aiidalab, theos, xps, tutorial
---
# Hands-on for AiiDAlab XPS calculation

[TOC]

## Feedback

After you finish the test, please spend 5 mins and give us your feedback: [e-mail]

## Step-by-step hands-on

### Sign up (Skip this if you already did)

Go to http://theossrv17.epfl.ch/ and sign up.

After signing up, you will get a message:

Please wait for the authorization from the admin. The admin will let you know when your account is ready.

### Login and open QeApp

Go to this link (from the EPFL VPN or the EPFL network): http://theossrv17.epfl.ch/

<img width=300 src=https://i.imgur.com/XJODOUH.png>

It will take a bit of time for the very first login. You will see a progress bar as shown below.

<img width=500 src=https://i.imgur.com/geRwWaN.png>

After login, you will find the Quantum ESPRESSO (QE) app on the page. Please click the QE logo to open the app.

<img wdith=300 src=https://i.imgur.com/SX7DBfz.png>

A new page opens, and you can start your new QeApp adventure with the guide at the top of the page.

<img widht=300 src=https://i.imgur.com/YRlqePb.png>

### Run calculation on the AiiDAlab machine

As shown at the top of the page, there will be four steps to carry out a QE calculation.

#### Step 1 Select a structure
You can select a structure from four sources.
- Upload file
- OPTIMADE
- AiiDA database
- From Examples

For the first task, please use the `Upload file` tab, and upload a H2O structure (Please download from [here](https://drive.google.com/file/d/1qUTDyn7emzVxvi7WqBLI0PF3br64JMCY/view?usp=sharing)).

In the end, click the `Confirm` button.

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#### Step 2 Configure workflow
Set the input parameters as follows:

- In the `Workflow` tab, please select ``Structure as is``, ``XPS``.
- In the `properties` section, please select ``X-ray photoelectron spectroscopy``
- In the `protocol` section, please select `fast` as the protocol for this calculation, in order to quickly get the result.

Then go to the `Advanced setting` tab, and the set the parameters which are highlighted as follows:

Then go to the `Spectroscopy setting` tab, and the set the parameters which are highlighted as follows:

In the end, click the `Confirm` button.

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#### Step 3 Choose computational resources.

##### Codes
We have set up a default computer (`localhost`) and the following codes:

- pw-7.0@localhost
- dos-7.0@localhost
- projwfc-7.0@localhost

For this calculation, you can use the default codes.

##### Resources
You can set the number of CPUs to 2 for the test.


Click the `Submit` button and the calcuation is launched.

:::info
*NOTE*:
There is no need to wait for the computation to finish: you can go head and submit a new calculation in parallel.
:::

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#### Step 4 Check the status and results.
The job may take ~2 minutes.

When the job is finished; then you can view the `XPS` in the `Step 4` section. If there is no result, please refresh the page, and choose the result at the top of the page in the ``Select computed workflow or start a new one``.


Here is the result:


#### Your own test calculation
Currently, only the XPS spectra of elements C, O, F and Si are supported.