def Storeligandnames(csv_file):
    """It identifies the names of the ligands in the csv file

    PARAMETERS
    ----------
    csv_file : filename of the csv file with the ligands

    RETURNS
    -------
    lig_list : list of ligand names (list of strings)
    """

    Lig = open(csv_file,"rt")
    lig_aux = []

    for ligand in Lig:
        lig_aux.append(ligand.replace(" ","_").replace("\n","").lower())

    return lig_aux