[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a nickel coordination entity and a bis(eta(5)-cyclopentadienyl)metal(II)."}, {"from": "gpt", "value": "[CH1-1][CH1-1][CH1-1][CH1-1][CH1-1][Ring1][Branch1].[CH1-1][C][=C][C][=C][Ring1][Branch1].[Ni]"}]