The quasiatomic approach is applied for the first time to the consideration and computation of angular distributions of (x-ray) photoelectrons scattered from surfaces. The anisotropic region surrounding an ionized-core atom in a specimen is regarded as acting as an electron-optical lens focusing or defocusing the initial (prescattering) photoelectron flux along various directions. The quasiatomic equations describing the photoelectron angular distributions as functions of the electron-optical properties of the surroundings are obtained, and stereographic projections of the photoelectron yield from model octahedral clusters (such as [SiF₆], [Na⁺F^- ₆] and [F^-Na⁺ ₆]) are computed with their help. Calculations of the low- and medium-energy photoelectron diffraction patterns show that the splitting of atomic [core^-1 El] transitions and the ll′-hybridization of the atomic continuous states dominate the focusing effect. It is revealed that: (1) a central role is played by the collective action of all of the atoms in the environment, whose symmetry compels the major directions of photoelectron yield to coincide with fourfold and threefold rotation axes rather than with directions to the nearest neighbours; (2) the low- and medium-energy diffraction patterns are highly sensitive to the electronic structure of the ionized atom and the integral electron-optical properties of the surroundings; and (3) the photoelectron angular distributions change dramatically when resonant inner-shell photoemission is achieved, and correlate with the symmetry of the highly excited molecular orbitals. The relationship between the description in terms of quasiatomic waves and that in terms of multiply scattered waves is discussed.