Hello Everyone,
I am doing some IRC calculation on some molecule
I used #p opt=(calcfc,ts,noeigentest) freq rmp2=full/6-311++g(3df,3pd) nosymm geom=connectivity this method and basis to optimize the TS and it looks it has a single imaginary frequency. Then I used to run IRC calculation with the opt TS as input and used the following method and basis functions #p rmp2=full/6-311++g(3df,3pd) irc (report=Cartesians,calcall,maxpoint
s=100,stepsize=5,maxcycle=512) Int=UltraFine scf=tight nosymm
But the output of the IRC looks very unusual, it is getting two IRC points with 0.00 reaction coordinate and one of them is very high energy and at the end of the calculation it do not converge. Please see the attached photo for details..
Now my question is why I am getting this unusual IRC points? How I can solve the problem?
Dear Lu, Thank you very much for your kind reply. As I have used too many steps (100 for both) in the reverse direction the IRC did not converged and the output looks unusual. Then I checked only reverse direction only with less number of points, it works fine..
Thank you..Again
If we get this kind of two points at 0.00 reaction coordinates, can we consider the other points' energy values (or this IRC values) as an authentic source or this might give us wrong results?
Dear Roy, Did you get the other IRC points as same or after this bug correction or energy values differed?
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