STRUCTURAL AND ELECTRONIC-PROPERTIES OF MOLTEN SEMIMETALS - AN AB-INITIO STUDY FOR LIQUID ANTIMONY

The structural and electronic properties of the crystalline semimetals As and Sb may be understood in terms of a Peierls distortion from the simple cubic structure bonds: as the (pp sigma)-band is exactly half- filled, the cubic structure is unstable against dimerization dividing the six nearest-neighbour bonds into three strong and three weak bonds and opening a deep gap in the electronic density of states at the Fer mi level. On the basis of neutron-diffraction experiments it has been suggested that some of the anomalous structural and electronic propert ies survive in the liquid phase. Here, an ab initio investigation of t he structural, electronic, and dynamic properties of molten Sb that is based on the full set of quantum-many-body forces is presented. The r esults confirm the picture of a Peierls-distortion in the liquid.