Changing the element name giving same output

[Debidutta Pradhan]

Hello Everyone,
I am a new vampire user. While practicing the Co.mat sample file provided in the package, if I am changing the material-name or material-element to Co or any other element like Ag, I am getting the same magnetization up to the last decimal. So my question is does the material-element consider the exact element in the calculation or it is explicitly dependent on other intrinsic parameter of the material.

Thanks

[gabo...@gmail.com]

Hi,

The material-name changes labeling in the output files and not the material's parameters.

The material-element changes the labeling in the rasmol program and not the material's parameters.

There is a better and more through description of what those do in VAMPIRE 7.0 manual at [1] on page 63 (pdf page 64) and page 68 (pdf page 69).

It might help to demonstrate that a little bit with the step by step example calculations below:

username@computername:~$ mkdir Co
username@computername:~$ cd Co
username@computername:~/Co$ cp ~/vampire/Co.mat .
username@computername:~/Co$ wget https://github.com/richard-evans/vampire-workshop/raw/refs/heads/master/input-files/1_intro/1a_Ni/input
...
username@computername:~/Co$ sed -i 's/Ni/Co/g' input
username@computername:~/Co$ echo "config:atoms" >> input

Here, you should see the material-name and material-element are set to Co and Ag initially, respectively:

username@computername:~/Co$ grep material- Co.mat
material[1]:material-name=Co
material[1]:material-element=Ag
username@computername:~/Co$ vampire-serial
                                                _          
                                               (_)        
                    __   ____ _ _ __ ___  _ __  _ _ __ ___
                    \ \ / / _` | '_ ` _ \| '_ \| | '__/ _ \
                     \ V / (_| | | | | | | |_) | | | |  __/
                      \_/ \__,_|_| |_| |_| .__/|_|_|  \___|
                                         | |              
                                         |_|              

                      Version 7.0.0 Jan 17 2026 11:00:31

             Git commit:
...
Simulation ended gracefully.
username@computername:~/Co$ grep Material log
17-01-2026 [12:21:41] Material 1 Co makes up 100 % of all atoms ( 6912 atoms )
username@computername:~/Co$ ~/vampire/util/vdc/vdc --xyz
|------------------------------------------------------------|
|              Vampire Data Converter for v5+                |
|------------------------------------------------------------|
Processing snapshot 00000000
username@computername:~/Co$ rasmol -xyz crystal.xyz
Options->Labels
Display->Ball&stick
Colours->Monochrome
Zoom: Hold shift + hold left click of mouse + move mouse up or down

username@computername:~/Co$ mv output output_Co

Here, we change the material-name and material-element to FM (which we give the meaning ferromagnetic) and Co, respectively:

username@computername:~/Co$ sed -i 's/material-name=Co/material-name=FM/g' Co.mat
username@computername:~/Co$ sed -i 's/material-element=Ag/material-element=Co/g' Co.mat
username@computername:~/Co$ vampire-serial
...

Here, you should see that with "material-name=FM", the previous label of Co has changed to FM:

username@computername:~/Co$ grep Material log
17-01-2026 [12:34:11] Material 1 FM makes up 100 % of all atoms ( 6912 atoms )
username@computername:~/Co$ ~/vampire/util/vdc/vdc --xyz
...
username@computername:~/Co$ rasmol -xyz crystal.xyz 

Here, you should see that with "material-element=Co", the previous label of Ag has changed to Co:

username@computername:~/Co$ mv output output_FM

Here, we change the exchange-matrix material parameter:

sed -i 's/exchange-matrix\[1\]=11.2e-21/exchange-matrix\[1\]=2.757e-21/g' Co.mat
username@computername:~/Co$ vampire-serial
...
username@computername:~/Co$ mv output output_exchange_2.757
username@computername:~/Co$ gnuplot
...
gnuplot> set xlabel "Temperature"
gnuplot> set ylabel "mean-magnetisation-length"
gnuplot> set key left bottom
gnuplot> p 'output_Co' u 2:7 w p, 'output_FM' u 2:7 w p, 'output_exchange_2.757' u 2:7 w p

No difference is seen between the magnetization vs temperature curves for output_Co (material-name=Co & material-element=Ag) and output_FM (material-name=FM & material-element=Co). Changing the exchange-matrix value to 2.757e-21 for Ni [2] from that of 11.2e-21 of Co significantly effects the curve as seen by output_exchange_2.757 of the plot:

[1] https://vampire.york.ac.uk/resources/vampire-manual.pdf

[2] https://github.com/richard-evans/vampire-workshop/blob/master/input-files/1_intro/1a_Ni/Ni.mat

Kind Regards,

Gavin

VAMPIRE user