  A full three-dimensional model for the calculation of the electronic
structure of semiconductor quantum dots (QD) and molecules (QDM) grown on high
index surfaces and/or in the presence of an external magnetic field is
presented. The strain distribution of the dots is calculated using continuum
elasticity and singe-particle states are extracted from the nonsymmetrized
eight-band k.p theory. The model properly takes into account the effects of
different substrate orientation by rotation of the coordinate system in the way
that one coordinate coincides with the growth direction, whereas the effects of
a tilted external magnetic field are taken into account throught the Zeeman
effect and employing a gauge invariant scheme based on Wilson's formulation of
lattice gauge theory. We point out the role of piezoelectricity for InAs/GaAs
QDs grown on [11k], where k = 1,2,3,4,5,7,9 and for QDMs containing eight
InAs/GaAs QDs grown on [11l], where l = 1,2,3. We predict the variation of the
transition energies of the QDM as a function of substrate orientation and
interdot distances in the molecule. We address the magnetic field direction
dependent variation of the electronic properties of QD and QDM.
