After NanoCAD has launched, take your time to read the text "Summary of NanoCAD Commands" at the top of NanoCAD window (Indicated by the green box in Image I).
You will get the basic idea how to use NanoCAD.
Click 'Clear' to remove the existing water molecule.
Click 'Structure'.
Image II - Nanocad editor, clear the water molecule
From 'Import Structure' click Database and then select CSD.
Image III - Select CSD to search for a new molecule
Search for ‘pentanediol’ (This would take about 20 seconds). From the list given, double-click on the second one ‘anti-2,4-Diphenylpentane-2,4-diol’.
Image IV - Pentanediol search results in CSD search
The complex will get ported into the Nanocad editor. Break the C bond between the highlighted atoms. Then select ‘Group’ and do ctrl+alt+click on the C atom (Highlighted in the image) of Phenyl. Then once the group is highlighted, click ‘Clear’ and remove the phenyl molecule.
Image V - anti-2,4-Diphenylpentane-2,4-diol complex in Nanocad editor
Similar to above remove the bind between the highlighted Cs and then remove the highlighted phenyl molecule similar to above.
Image VI - anti-2,4-Diphenylpentane-2,4-diol complex with removed atoms
Ctrl+click on the gray background area to center the molecule. You can rotate the molecule by click and drag.
Image VII - Pentanediol acid
Click 'Add H' button – on the lower righthand corner.
Image VII - Add H to the molecule
Import the molecule as a Gaussian input
Image VIII - Importing as Gaussian input
Read and say OK, to the confirmation and warning message.
Image IX - Confirmation and warning messages on exporting molecule.
Above input file is then exported into Gaussian Editor GUI. Add the Methods and Wavefunction.
Image X - Add Method B3LYP & Wavefunction
Add Basis set
Image XI - Add Basis set
Add Job Type
Image XII - Add Job type
Add Keywords, 'Common Keywords' → Pop and from the pop-up window select 'Reg' and click 'Done'. From 'Other Keywords' select GFInput, GFPrint and IOp. From IOp window add Overly=6, Option=7 and Value=3 click 'Done' on both windows.
Image XIII - Adding Keywords to the Gaussian input
In Gaussian GUI add
%nproc - 16
%mem - 3000
Checkpoint File - Pentane23diol
Check Use #P
Add job title and Description - Pentane23diol #P RB3LYP/cc-pVDZ Pop=(Reg) GFInput GFPrint Iop(6/7=3) Opt Freq