[{"from": "human", "value": "Create a molecule with the structure as the one described. The molecule is a branched alkane that is heptane carrying two methyl groups each at positions 2 and 6, and one methyl group at position 4."}, {"from": "gpt", "value": "[C][C][Branch1][#Branch2][C][C][Branch1][C][C][Branch1][C][C][C][C][C][Branch1][C][C][Branch1][C][C][C]"}]