Modifying hcp.cpp file to create trigonal or hexagonal lattice

[Sotiris Fragkos]

Dear Vampire users and developers,

I want to make Vampire-skyrmion simulations on 1T- CrTe2 (S.G. 164) with DMI which has trigonal symmetry. 

At first, I did several calculations by using the .ucf file, including Curie temperature and hysteresis loops calculations, which at first seemed correct.

Later on, I performed Field-Cooling calculations to visualise skyrmions, where I noticed that the printed spin configurations (using the script visualise.sh - gnuplot) create a cubic (or tetragonal) lattice, instead of a hexagonal.

This makes me believe that the .ucf file cannot create a trigonal (or hexagonal) lattice (correct me if I'm wrong), and for that reason, subsequently, I tried to modify the hcp.cpp in the source code in order to obtain the desired structure of CrTe2.

Since Te atoms are non-magnetic, I only kept Cr atoms for my simulations. Without the Te atoms, the lattice is now hexagonal instead of trigonal, which makes the things simpler.

I did various test but I couldn't obtain the expected results. I successfully obtained the hexagonal structure (with perpendicular lattice vectors) but the Curie Temperature curves are not of the form m(T)=(1-T/Tc)^β. 

I attach the hcp.cpp file in case you can help me and notice something wrong.

Best regards,

Sotirios Fragkos

PhD Student

NCSR Demokritos, Athens, Greece

https://scholar.google.gr/citations?user=Ua5AwZIAAAAJ&hl=en

https://inn.demokritos.gr/prosopiko/s.fragkos/