def get_top_element_count(mol, top):
    """
    Returns the element count for the molecule considering only the atom indices in ``top``.

    Args:
        mol (Molecule): The molecule to consider.
        top (list): The atom indices to consider.

    Returns:
        dict: The element count, keys are tuples of (element symbol, isotope number), values are counts.
    """
    if not isinstance(top, list):
        top = list(top)
    element_count = {}
    for i, atom in enumerate(mol.atoms):
        if i in top:
            key = (atom.element.symbol, atom.element.isotope)
            if key in element_count:
                element_count[key] += 1
            else:
                element_count[key] = 1
    return element_count