Re: About restarting QM-MM simulation

From: Gerard Rowe (
Date: Thu Feb 14 2019 - 10:38:06 CST


You probably already figured it out, but for others who may be reading, the error you experienced was an Orca syntax error. The %maxcore ### line is a single-line command that doesn't get terminated with "end". Only input blocks like SCF, BASIS, and PAL should be terminated with "end". It's confusing because it starts with %, but "%maxcore ####" is setting a global variable rather than initializing an input block.


From: <> on behalf of Francesco Pietra <>
Sent: Thursday, February 14, 2019 9:46 AM
To: Eric Smoll;
Subject: Re: namd-l: About restarting QM-MM simulation

On a fresh approach, a few hours later, the following interpretation

qmConfigLine "! UKS BP86 RI SV def2/J enGrad SlowConv"
qmConfigLine "%%maxcore 2500 %%pal nproc 34 end"
# qmConfigLine "%%pal nproc 34 end"

allows the simulation running.

On Thu, Feb 14, 2019 at 11:17 AM Francesco Pietra <<>> wrote:
Hi Eric, perhaps you can help me further about an error message concerning input to ORCA that is unclear to me

setting in namd conf file about orca:
qmConfigLine "! UKS BP86 RI SV def2/J enGrad SlowConv"
qmConfigLine "%%maxcore 2500 end"
qmConfigLine "%%pal nproc 34 end"
qmConfigLine "%%scf MaxIter 5000 end"
qmConfigLine "%%output Printlevel Mini Print\[ P_Mulliken \] 1 Print\[P_AtCharges_M\] 1 end"

Error shown in /0/..TmpOut
[file orca_main/maininp1.cpp, line 14628]: ERROR: expect a '$', '!', '%', '*' or '[' in the input

By commenting out the line
qmConfigLine "%%maxcore 2500 end"
the simulations starts regularly. The default mem 1024 gave rise to warning in /0, while 2500 per core corresponds to less than 75% mem available on the node.
I must have been unable to interpret correctly the Example furnished by ORCA, or there is something else that I don't understand.
%maxcore 3000
nprocs 6
 Thanks for advice

On Wed, Feb 13, 2019 at 7:48 PM Eric Smoll <<>> wrote:

You asked how to increase the number of SCF iterations above the default. Try something like this:

MaxIter 500


On Wed, Feb 13, 2019 at 8:34 AM Francesco Pietra <<>> wrote:
How can NAMD-ORCA QM-MM simulations be correctly restarted? I mean in the context of namd.config in Example1 tutorial:

structure XXX_A1_box_ion.psf
coordinates XXX_A1_box_ion.pdb

# Output Parameters
binaryoutput no
outputname XXX_A1_out
outputenergies 1
outputtiming 1
outputpressure 1
binaryrestart yes
dcdfile XXX_A1_out.dcd
dcdfreq 1
XSTFreq 1
restartfreq 100
restartname XXX_A1_out.restart

In particular when no SCF convergence was not yet reached (in favorable cases, info says that SCF convergence is close to be reached), so that XXX_A1_out.restart was not provided.

I was also unable to find on ORCA manual how to increase the number of SFC iterations above the default 125.

Thanks for advice
francesco pietra
PS I understand that the ORCA calculation can be carried out separately but I have some reasons now to let NAM-ORCA working together.

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