A computationally simple method of calculating nonspherical charge distributions in solids from linear-muffin-tin-orbital band-structure calculations is described. The charge distribution is described accurately in the region between muffin-tin spheres in terms of wave functions based on "pseudo-muffin-tin" orbitals. The nonsphericity inside the spheres as described by the same orbitals is less accurate. For several applications, however, this is not serious. The density can easily be expressed as a Fourier series, which is convenient for calculation of interactions. As an example of application the scheme is used to calculate multipole moments and electrostatic interactions between Wigner-Seitz cells in a monoatomic crystal.

• Received 22 November 1983

DOI:https://doi.org/10.1103/PhysRevB.29.5547