87 citations · 96 across the 6 of their papers we have counts for
6 papers
Polarization and Structure of Small Clusters
W. Geertsma
In this paper we report the structure of the Li4Ge4 cluster as a function of charge transfer and polarizability. We find that for small charge transfer (Q < 0.5) this cluster has t…
Polarization and Covalency in Alkali-Tetralide Clusters
Wiebe Geertsma
In this paper we discuss the structure of A4M4 alkali(=A)- tetralide (= M) (= group 14) clusters. Without polarization these polyions consist of a central tetralide tetrahedron wit…
Spin order on pyrochlore lattices studied by the Self-Consistent Cluster Approach
Wiebe Geertsma
In this paper we present a study of magnetic order of quantum Heisenberg spins on pyrochlore type lattices: a lattice of corner sharing tetrahedra. We use the Cluster Variation App…
A study of the electronic properties of liquid alkali metals. A self--consistent approach
W. Geertsma, D. Gonzalez, L. H. Gonzalez
We study the electronic properties (density of states, conductivity and thermopower) of some nearly--free--electron systems: the liquid alkali metals and two liquid alloys, Li-Na a…
Superexchange and lattice distortions in the spin--Peierls system CuGeO3
Wiebe Geertsma, D. Khomskii
We present a study of the nearest--neighbor (nn) and next-nearest-neighbor (nnn) exchange constants between magnetic Cu centers of the spin-Peierls material CuGeO3. The dependence…
Elementary excitations, exchange interaction and spin-Peierls transition in CuGeO
D. Khomskii, W. Geertsma, M. Mostovoy
The microscopic description of the spin-Peierls transition in pure and doped CuGeO_3 is developed taking into account realistic details of crystal structure. It it shown that the p…