  A new method of the phase determination in X-ray crystallography is proposed.
The method is based on the so-called "minimum charge" principle, recently
suggested by Elser. The electron density function $\rho$ is sought in the form
$\rho({\bf x})=|\psi({\bf x})|^2$, where $\psi$ is an $n{-component}$ real
function. The norm $\int|\psi({\bf x})|^2 d{\bf x}$ is minimized under the
constraint imposed by the measured data on the amplitudes of Fourier harmonics
of $\rho$. Compared to the straightforward implementation of the "minimum
charge" scheme, the method attenuates the Gibbs phenomenon and is also capable
of extrapolation of the diffraction data beyond the set of measured amplitudes.
The method is applicable to quasicrystals under the condition that the number
of components $n$ of the function $\psi$ is bigger than the dimensionality of
the ``atomic surface''. It is successfully tested on synthetic data for
Fibonacci chain and the octagonal tiling. In the latter case the reconstructed
density map shows the shape of the atomic surface, despite relatively low data
resolution.
