SMD calculation for an undefined solvent

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Andreas Mavrandonakis

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May 4, 2021, 1:40:56 PM5/4/21
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Dear all,
I am trying to calculate the solvation free energy of an organic molecule in an undefined solvent with SMD.
Following the instructions from the Wiki "The user can specify a solvent that is not on the list by omitting the solvent keyword and instead introducing user-provided values for the following solvent descriptors:.." , I could set up a calculation , since I know all the descriptors of my solvent.
So, the input looks like this:

cosmo
 do_cosmo_smd true
 dielec 37.2190
 sola  0.0000
 solb  0.7400
 solc  0.0000
 solg 49.5600
 solh  0.0000
 soln  1.4305
end

These parameters have been taken from the DMF. I wanted to test, if NWChem would give me the same results as by using "solvent dmf" . 
NWChem runs fine without any problem.
However, when i look at the output file, I noticed that the program calculates it as an aqueous SMD model and reports:

 solvent parameters
 solvname_short: h2o
 solvname_long:  water
 dielec:       37.2190
 dielecinf:     1.7769
 aqueous SMD model solvent descriptors
 dielec:       37.2190
 sola:          0.0000

It seems that it neglects all other solvents descriptors: solb, solc, solg, solg , and it only reads dielec, sola and soln.

Do you have any idea, how I can properly run the SMD calculation for an unspecified solvent?
Or is there a bug in NWChem ?
Thank you.

Best,
Andreas

Edoardo Aprà

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May 4, 2021, 2:40:29 PM5/4/21
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We can definitely say you have uncovered a bug.
However, there is a workaround to trigger Cosmo SMD to switch to a non aqueous solvent.
You have to supply a solvent keyword for a non existing solvent (e.g. solvent mysol)
Here is the related SMD input section
cosmo
 do_cosmo_smd
 dielec       37.2190
 dielecinf    2.0463

 sola          0.0000
 solb          0.7400
 solc          0.0000
 solg         49.5600
 solh          0.0000
 soln          1.4305
 solvent mysol
end

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