def get_neighbours(x):
    """
    Get the neighbours of a point given the coordinates (6 points).
        
    Parameters
    ----------

    x : tuple
        3d coordinates of the center point.

    fname : string
        File name.
        
    Returns
    ----------
    
    neighbours: list
        List of 3d coordinates of the neighbours.
    
    """
    r = [-1, 0, 1]
    neighbours = [(x[0]+i,x[1]+j,x[2]+k) for i in r for j in r for k in r 
        if (i,j,k)!=(0,0,0)
        and abs(i)+abs(j)+abs(k) < 2]
    return(neighbours)