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Hi<BR>
i tried to use the linear relation between omega(k)/k (near Gamma point in TA branch of phonon band structure of AlAs) in the [000]-[100] direction, to calculate the sound velocity along [100] and finally estimate the elastic constant C_44 of it(AlAs):<BR>
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v_transverse[100]=sqrt(C_44/density)<BR>
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but i have orders difference with the experimental value(56.6 Gpa). I wonder if anyone(tried the same) could tell me what may be wrong in my calculation? I calculated the desired velocity as 506m/s (by the mean of the 6th example's results)<BR>
Thanx for any comment<BR><br /><hr />Explore the seven wonders of the world <a href='http://search.msn.com/results.aspx?q=7+wonders+world&mkt=en-US&form=QBRE' target='_new'>Learn more!</a></body>
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