Mod:Hunt Research Group/orca6 custom solvent

Using Custom Solvation Parameters in ORCA

This section explains how to use a custom basis set in ORCA. The only caveat is that you have to specify a "dummy solvent" as a placeholder in the route line and then you can use %cpcm block later and the software will use the parameters in %cpcm block. Its better to use a "dummy solvent" that has a close epsilon value to the custom parameters you are using.

Below is an example optimization file of CH₃I that uses the custom solvent parameters. Comments in front of those parameters are self-explanatory.

%MaxCore 1000
%pal nprocs 16 end
# Optimization of CH3I with SMD [C4C1Im][SCN] (Dichloromethane is a placeholder).
!B3LYP NoAutoStart TightSCF def2-SVP RIJCOSX def2/J def2-SVP/C SMD(1,2-dichloroethane)
%cpcm
  smd18 true          # SMD18 has updated radius for I
  epsilon 13.7        # static dielectric
  soln 1.5392         # refractive index = sqrt(epsinf)
  sola 0.18           # H-bond acidity
  solb 0.52           # H-bond basicity
  solc 0.231          # aromatic carbon fraction
  solg 68.34          # surface-tension descriptor
  solh 0.0            # electronegative-halogenicity
end
%basis
NewECP I "def2-ECP" end # Define ECP for Iodine atom
end

* xyz 0 1
 C                  0.00000000    0.00000000   -1.79947500
 H                  0.00000000    1.03191700   -2.12804700
 H                 -0.89366600   -0.51595800   -2.12804700
 H                  0.89366600   -0.51595800   -2.12804700
 I                  0.00000000    0.00000000    0.32417000
*