What are the characters for the operations C2, C4, d, and v(xz) respectively, on the LCAO (L1+L3) (L2+L4) in the square planar metal complex

What are the characters for the operations C2, C4, σd, and σv(xz) respectively, on the LCAO Ψ(L1+L3) – Ψ(L2+L4) in the square planar metal complex ML4? The arrangement of the four ligands is shown in the structure.

y. L4 L1 L3 L2