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<P><FONT face=Arial size=2>Hi cpmd users,</FONT></P>
<P><FONT face=Arial size=2>I've got 3 little questions..</FONT></P>
<P><FONT face=Arial size=2>1) I'm doing a md run of a molecule surrounded by
water molecules. In order to check if the forces acting on the molecules are not
too large, i'd like to check out the forces acting on them (since i didn't do a
geometry optimalization at the beginning). I checked out the manual and found
that it is possible to print the acting forces during the trajectory in the
TRAJECTORY file. Since the md run is 'finished' it seems to be a little late for
that..<BR>But now I was wondering what the initial forces acting on the atoms
would be. Since they are listed in the output file that seemed not to be a
problem. But what are the units of the forces? They are not mentioned in the
manual, so i suppose it's a.u.? If it it, what's the conversion to convert them
to dyne, Newton,.. or something else?</FONT></P>
<P><FONT face=Arial size=2>2) Before I did a md run, i checked out some dft
functionals to describe the geometry of the molecule. I got convergence for C=C,
C-H, more or less convergence for S-N but the C-S bound seems not to
convergence at all (the C's from a aromatic system and C is attached to it).
Does anyone have an idea why that could be? </FONT></P>
<P><FONT face=Arial size=2>3) In the manual, the GGA functional is mentioned.
But what's the exact functional behind that GGA implemented in cpmd? Since GGA
stands for Generalized-gradient-approximation, it doesnt give me any new
information..</FONT></P>
<P><FONT face=Arial size=2>Thanks in a</FONT><FONT face=Arial
size=2>dvance!</FONT></P>
<P><FONT face=Arial size=2></FONT> </P>
<P><FONT face=Arial size=2>Christopher</FONT><FONT face=Arial
size=2><BR>Undergrad. Student<BR>University of Antwerp</FONT></P><DIV><FONT face='Arial' color=#000000 size=2></FONT> </DIV></BODY></HTML>