Reg: units of thermal conductivity in green kubo relation

Dear all,

I am unable to match the unit of thermal conductivity by Green Kubo relation in LAMMPS. According to LAMMPS heat flux (energy* velocity) should be multiplied by (V/3kbT^2) which means unit of k = (Jm/s)(m^3/JK)=(m^4/sK).
Unit is not matching with W/mK.

Please help me where I am doing wrong. Thanks!