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<p>Dear Mahdi,</p>
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<p>tstress=.true. prints the Cauchy stress. It is the internal instantaneous stress from the Calculation. The other stresses are two-point stresses e.g. relative to some initial and final configurations (for deformations).<br>
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<p>The quantum mechanical stresses are the internal stresses at the very cell parameters and Volume of the SCF calculation. They correspond basically to the expansion parameters of the total energy with respect to infinitesimal deformations.
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<p> BR Nico<br>
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<p>Nicolas Hoermann</p>
<p>Theory and Simulation of Materials (THEOS)</p>
<p>EPFL, Lausanne<br>
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Dear all,<br>
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I know If I set tstress=.true. the stress tensor will be computed and<br>
printed. but What's the kind of the Stress Tensor QE dose print? for<br>
example Cauchy,<br>
true, Kirchhoff, PK2, ...<br>
I am trying to calculate second Piola–Kirchhoff (PK2) stresses with QE.<br>
Any suggestions or comments are appreciated.<br>
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Sincerely<br>
Mahdi<br>
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*Mahdi FaghihNasiri*<br>
Department of Physics<br>
Shahrood University of Technology<br>
Shahrood,Iran**
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