Step 1, Request the files¶
The download of the line lists can either be done manually through the website, or in a more automated way, by using navigation scripts.
Before the VALD data can be acessed, one has to register on the VALD website.
Attention, there is a limit of 100000 transition lines per query. Some species have more lines than that. Is this case, the wavenumber ranges have to be split into two parts. This is especially the case for Fe and Cr.
Method A, manual request¶
Register with email address
Choose Mirror Server
Unit selectionsand select:
Energy level units: cm-1
Give wavelenths in medium: vacuum
Wavelength units: cm-1
Van der Waals syntax: Default
Isotopic scaling: Off
check the units, they must be
Energy unit: 1/cm - Medium: vacuum - Wavelength unit: 1/cm - VdW syntax: default
Enter Starting wavenumber, e.g. 0.001
Enter Ending wavenumber : e.g. 1000000
Enter Element: e.g Fe 1, (ionizaion number = 1 means neutral)
Extraction format : Long format
Retrieve data via : FTP
Include HFS splitting
Enter a comment in
Optional comment for request, for example the element and ionization number.
Method B, using scripts¶
Also this mehod requires to first visit the web interface manually and to choose the correct units, the same way as Method A. After that, the vald_request.py script can navigate the webiste and fill in the necessary webforms. For this, a geckodriver needs to be installed.
python3 vald_request.py -Z <z> -I <i> -u <email address>
<z>is the atomic number and
<i>the ionization state (i = 0 is neutral)
The email address must be the same as the user account from the VALD website.
Step 2, download the files¶
After a few minutes you will get an email from VALD with a link to download the data file.
Method A, manual download¶
Download the file and unpack it. Rename the file to
E.g VALD2600.dat for Z = 26, I = 0 (I = 0 means neutral atoms).
Method B, using scripts¶
The requested files are stored temporarely on the VALD webiste with a name similar to
SimonGrimm.4199418, where the first part is the user name, and the second part is the
job number. The vald_download.py script can download all requested files, scan which element
they contain and rename them according to the element number.
python3 vald_download.py -jobstart <start> -jobend <end> -jobname <name>
The name is the user name from the VALD webiste, e.g SimonGrimm. The jobstart is the first jobnumber (check email from VALD) .e.g 4199418. The jobend is the last jobnumber (check email from VALD) .e.g 4199420.
The files are renamed as
Step 3, partition function files¶
Partition functions are not available in the VALD database. Therefore we use the partition functions calculated from the NIST database.
Step 4, calculate natural broadening coefficients and create the binary files and
< species >.param files¶
For many species, the vald database provides broadening coefficients, but not for all. The missing coefficients are calculated in this step. That can take a while to complete.
python3 vald.py -Z <z> -I <i>
This step creates the
< species >.param and the
Step 5, data path¶
Include the path of the directory, which contains the obtained binary
*.pf partition function files and the
*.param file to
param.dat file under
Vald provides reference files for each species. We rename these
the same way as the data files. When using data from VALD, all these references
must be cited in publications.
We list here also the citation conditions from VALD:
A short note on using VALD data : The VALD data and services are provided free of charge on the following conditions: 1. If VALD has been used in your research work, you agree to include the acknowledge below as well as citations to the following papers where appropriate: "This work has made use of the VALD database, operated at Uppsala University, the Institute of Astronomy RAS in Moscow, and the University of Vienna." Ryabchikova T., Piskunov, N., Kurucz, R.L., et al., Physics Scripta, vol 90, issue 5, article id. 054005 (2015), (VALD-3) Kupka F., Ryabchikova T.A., Piskunov N.E., Stempels H.C., Weiss W.W., 2000, Baltic Astronomy, vol. 9, 590-594 (2000), (VALD-2) Kupka F., Piskunov N.E., Ryabchikova T.A., Stempels H.C., Weiss W.W., A&AS 138, 119-133 (1999), (VALD-2) Ryabchikova T.A. Piskunov N.E., Stempels H.C., Kupka F., Weiss W.W. Proc. of the 6th International Colloquium on Atomic Spectra and Oscillator Strengths, Victoria BC, Canada, 1998, Physica Scripta T83, 162-173 (1999), (VALD-2) Piskunov N.E., Kupka F., Ryabchikova T.A., Weiss W.W., Jeffery C.S., A&AS 112, 525 (1995) (VALD-1) 2. You also agree to reference to original source(s) of the line data that are important for your research. A complete list of references is available from the bibliography section of the VALD manual. A short list of references is compiled and sent to you with every reply from VALD.