TURBOMOLE Users Forum
TURBOMOLE Modules => Jobex: Structure Optimization and Molecular Dynamics => Topic started by: tjmustard on April 25, 2012, 09:27:09 PM
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Hi all,
I currently have an issue with a RIJK jobex optimization failing on the first RDGRAD. Has anyone seen this error?
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density functional
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Becke-3-Parameter hybrid functional: B3-LYP
exchange: 0.8*LDA + 0.72*B88 + 0.2*HF
correlation: 0.19*LDA(VWN) + 0.81*LYP
iterations will be done with small grid
spherical integration : Lebedev's spherical grid
spherical gridsize : 3
i.e. gridpoints : 302
value for diffuse not defined
radial integration : Chebyshev 2nd kind (scaling 3)
radial gridsize : 3
integration cells : 16
partition function : becke
partition sharpness : 3
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RDGRAD - INFORMATION
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0 shell pairs used , remaining= 3570
Task specific shell ranges
DYNAMIC TASKS
#task #minshell #maxshell
3 42 60
4 2 42
5 1 2
maximum shell range = 41
Local memory allocated for RDGRAD: 1 MiB
PQ decomposition by fast serial Cholesky
SEVERE ERROR from node: 0 symink not yet adapted to gradients
error in gradient step (1)
Thank you,
TJ Mustard
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Hello,
RI-K is not parallelized at all in rdgrad. The method was developed as a way to speed up Hartree-Fock when doing MP2 calculations. RI-K works best with medium-sized molecules and larger basis sets (at least TZVP) and if you have enough memory to store the RI matrices completely in RAM.
For DFT jobs the basis sets in use are usually smaller, so here RI-K can be even slower than the conventional DFT calculation.
B3-LYP works really good with RI-J only (i.e. without RI-K) also in parallel. Here a (so called) linear scaling exchange algorithm is being used which makes the calculation faster than the non-RI-J case by a factor of two and more (depends on the size of the molecule, but if you run it in parallel, I assume that it is not a small job).
Regards,
Uwe