Origins of the File Names "OSZICAR" and "XDATCAR".

[hszhao.cn@gmail.com]

Hello VASP Community,

I've been utilizing VASP for my computational studies and have come across various output files such as OSZICAR and XDATCAR. While I understand the purpose and contents of these files, I'm intrigued by the origins of their names.

Could anyone shed light on the history or reasoning behind the naming conventions for these files? Specifically, what do "OSZICAR" and "XDATCAR" stand for, and how were these names chosen? Insights into the naming conventions used in VASP and the historical context would be greatly appreciated.

Thank you for sharing your knowledge and helping to deepen my understanding of VASP's functionality and history.

Best regards,
Zhao

[martin.schlipf]

That is an interesting question. I will inquire if there is some history to these file names.

At the moment, my best guess is that OSZICAR is named after the German word "oszillieren" (oscillate) because it monitors oscillations in the total energy. For XDATCAR, the X was quite commonly used at the time (c.f. xcrysden or xmgrace) so it just means position data.