The high-resolution X-ray diffraction analysis and plane-wave density functional theory were applied to the investigation of charge density distribution in the donor-acceptor complex of AuCl with PPh3. The approach allows us to estimate the atomic charges, the charge transfer, the energy of weak interactions (Au center dot center dot center dot H, Au center dot center dot center dot C, H center dot center dot center dot Cl, etc.), and Au-P bond energy directly from the experimental data.