The liquidation fee on Omni is currently set to 0.5%.
When a liquidation is triggered:
Longs: Force-liquidated at the Bid Price - 0.5%
Short: Force-liquidated at the Ask Price + 0.5%
Because Omni uses a Partial Liquidation mechanism, this fee is only applied to the portion of the position that is force-closed to return your account to a healthy margin level.
For more details on the liquidation fees, visit the Variational Docs.