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<DIV><FONT face=Arial size=2>Dear all:</FONT></DIV>
<DIV><FONT face=Arial size=2>I'm new to PWscf. I tried the first example which
includes the total energy calculation of Si. The result I got from this example
was: </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>! total
energy
= -15.84452726 Ry</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I believe this is for the total energy of the two
Si atoms system. However, from the reference data here:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://physics.nist.gov/PhysRefData/DFTdata/Tables/14Si.html">http://physics.nist.gov/PhysRefData/DFTdata/Tables/14Si.html</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The total energy is -288.198397 a.u.. The
caluclated data is very different from this. Is this because of using of
pesudopotential? How can I get the real totoal energy? </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I would appreciate any help!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thank you!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Tengfei</FONT></DIV></BODY></HTML>