second derivatives with electrostatic pointcharges

[Futera]

Hello,

I tried to compute frequencies by aoforce with some electrostatic pointcharges included. Structure was minimized with tight convergency criteria but there are many imaginary frequencies and in aoforce output is no mention about including pointcharges in calculation of second derivatives. What's wrong? Should I add some keyword or is it bug in aoforce? I'm using Turbomole 5.9.

Best regards

Zdenek

[christof.haettig]

Did you fix any coordinates?

[Futera]

No, all coordinates except point charges were free and optimized.

[christof.haettig]

How did you include the pointcharges? aoforce does not account for pointcharges introduces with the option $pointcharges. But if you introduce them as additional nuclei in $coord without basis functions and with individually asigned charges in $atoms the aoforce code should give the correct results.

Best regards,
C.H.

[Futera]

Thanks for your answer. I tried this specification of point charges but unfortunately aoforce ended with error:

Code: [Select]

Dummy atoms without basis are not allowed in force !
so I think that aoforce really cannot work with electrostatic pointcharges. Or is there any other option which I missed?

[christof.haettig]

I see... you've "small" charges. The trick only works for charges larger than 0.1 au. Atoms with smaller charges are recognized as "dummies" which the force code doesn't treat correctly.

Christof

[yva82]

Are there any updates on that issue with the pointcharges and the second derivatives? Is maybe a newer version of TM now able to handle pointcharges with charges smaller than 0.1 a.u. ?



Yvonne