def METHOD_NAME(qrange, deltam):
    """Iterate over the Q values
    Parameters
    ----------
    qrange:
        upper and lower bounds of q range
    deltam:
        Fractional mismatch between neighbouring tiles
    Returns
    -------
    Q-value:
        Q value for Q-tile
    """
    # work out how many Qs we need
    cumum = log(float(qrange[1]) / qrange[0]) / 2**(1/2.)
    nplanes = int(max(ceil(cumum / deltam), 1))
    dq = cumum / nplanes
    for i in range(nplanes):
        yield qrange[0] * exp(2**(1/2.) * dq * (i + .5))
    return