def get_vecang_cell(cryst, uc=None):
    '''
    Compute A,B,C, alpha,beta,gamma cell params
    from the unit cell matrix (uc) or cryst.
    Angles in radians.
    '''
    if uc is None:
        uc = cryst.get_cell()
    ucv = [uc[i, :]/norm(uc[i, :]) for i in range(3)]
    uca = [acos(dot(ucv[(i+1) % 3], ucv[(i+2) % 3])) for i in range(3)]
    return [norm(uc[i, :]) for i in range(3)] + uca
Compute A,B,C, alpha,beta,gamma cell params
    from the unit cell matrix (uc) or cryst.
    Angles in radians.