An analysis of crystal binding and structural phase transition is presented using an analytical potential form for the overlap repulsive energy derived by Harrison from quantum mechanical considerations. The potential model is applied to calculate the cohesive energies, bulk modulus, and its pressure derivative for fifteen alkaline-earth chalcogenides and fourteen alkali chalcogenides. Calculated values of bulk modulus are found to exhibit empirical correlationship with unit cell volume. The problem of relative stability and structural phase transition is also investigated for alkaline-earth chalcogenides. Values of transition pressure are obtained and found to present good agreement with experimental data.Mit einer analytischen von Harrison aus quantenmechanischen Betrachtungen abgeleiteten Potentialform wird eine Analyse der Kristallbindung und der strukturellen Phaseniibergiinge durchgefuhrt. Das Potentialmodell wird zur Berechnung der Kohiisionsenergie, des Elastizitiitsmoduls und seinen Druckableitnngen von funfzehn Erdalkalichalkogeniden und vierzehn Alkalichalkogeniden benutzt. Es wird gefunden, da13 die berechneten Werte des Elastizitiitsmoduls eine empirische Korrelation mit dem Volumen der Einheitszelle aufweisen. Das Problem der relativen Stabilitiit und strukturellen Phasenubergiinge wird auch fur Erdalkalichalkogenide untersucht. Werte des Ubergangsdruckes werden erhalten und gefunden, da13 sie gut mit experimentellen Werten ubereinstimmen.

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Submission of an original paper with copyright agreement and authorship responsibility.I (corresponding author) certify that I have participated sufficiently in the conception and design of this work and the analysis of the data (wherever applicable), as well as the writing of the manuscript, to take public responsibility for it. I believe the manuscript represents valid work. I have reviewed the final version of the manuscript and approve it for publication. Neither has the manuscript nor one with substantially similar content under my authorship been published nor is being considered for publication elsewhere, except as described in an attachment. Furthermore I attest that I shall produce the data upon which the manuscript is based for examination by the editors or their assignees, if requested.Thanking you.