TITLE:

A density functional study of total energy profiles of As, Sb and Bi along selected deformation
paths applied to epitaxial thin films.


AUTHORS:

Martin Zouhar and Mojmir Sob


ABSTRACT:

We present an ab initio study of structural properties of As, Sb and Bi in their A7 ground state
and three cubic modifications.


The cubic structures and corresponding trigonal deformations are described using three parameters
of the ground state structure A7 - atomic volume, trigonal distortion and an internal parameter 'u'
of the A7 structure (for cubic structures, u=0.25).


Employing pseudopotential VASP code, we calculate the total energies along selected deformation
paths, display them in contour plots as functions of the above-mentioned parameters and identify
energy extrema corresponding to the four basic structures.


The calculated energy profiles are used to determine the structure parameters of As, Sb and Bi thin
films on various substrates with the (111) cubic or (0001) hexagonal geometry.


An overall good agreement with available experimental data motivates us to provide many theoretical
predictions which may challenge experimentalists for a deeper study of these systems.