I have convert the xyz file of my cluster to POSCAR via VESTA. But It failed. Noi atom shown when I Upload the new generated poscar. How to fix this problem?
how exactly did you convert the xyz file to a POSCAR via VESTA? The "problem" with xyz files is that they do not contain information about your box size which is a crucial part of a POSCAR file. VESTA still can display xyz files, but visualizing a POSCAR file derived from an xyz file without adding further information about the box will probably result in an error as you encountered.