iOpenShell » Q-Chem specific questions » Error when running FREQ calculations with (any) PCM

Error when running FREQ calculations with (any) PCM

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Author Post
Member
Registered: Jun 2018
Posts: 1
Hello.

I was attempting to run an opt -> freq -> single-point workflow, with PCM solvent model (IEFPCM) in all three.

My input file for the FREQ stage (I split each stage into a separate Q-Chem input file in order to ease debugging) looks like so:

$molecule
0 1
C -0.3544572190 1.1223444518 0.1528599422
O -1.1516870463 0.0000517513 0.2659941908
C 1.0504483595 0.6628084222 -0.0458743354
O -0.7959867144 2.2208522184 0.2155102710
C -0.3550154687 -1.1226383282 0.1528887892
C 1.0501164745 -0.6638085372 -0.0458646623
O -0.7970806432 -2.2209295342 0.2155749379
H 1.8699165610 1.3550890697 -0.1619593359
H 1.8692395881 -1.3564980690 -0.1619399785
$end

$rem
job_type = freq
basis = 6-31g*
max_scf_cycles = 200
gen_scfman = true
scf_algorithm = diis
method = m06-2x
solvent_method = pcm
$end

$pcm
heavypoints 194
hpoints 194
radii uff
theory iefpcm
vdwscale 1.2
$end

$solvent
dielectric 8.93
$end

When I try to run that input file (which, with all references to pcm and solvents removed, runs perfectly), I get the following message:

Calculating MO derivatives via CPSCF


PCM Hessian for IEF-PCM not available.

I attempted to run with different theory, thinking that it might specifically be IEF-PCM that is the problem. They all aborted the job. However, I received no error message. For instance, with CPCM, the job aborted, and the output file ended with:

Calculating MO derivatives via CPSCF
Computing fast CPCM-SWIG hessian.

Does anyone know why the hessian computation is causing such problems here? If there another way to perform these calculations, or should I just give up on calculating FREQ with PCM?

Thank you in advance for your help.
Administrator
Registered: Oct 2017
Posts: 17
It looks like a bug. Does finite difference work?

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iOpenShell » Q-Chem specific questions » Error when running FREQ calculations with (any) PCM