- Yes you can sync your Lightroom catalogs between two computers.
- You just need to have the following files copied to some external drive and take them to the other computer :
- Lightroom catalog.lrcat
- Lightroom catalog previews.lrdata
- Lightroom catalog smart previews.lrdata
Check the below link for more information;
Sarika has you pointed in the right direction.
The easiest way to use LR on two computers is to put your photos and your LR catalog on an external drive and move that drive from computer to computer as needed.
Also check "store presets with Catalog" in Preferences>Presets... so the presets are on the external not on the computer and always available.
The direct answer to your question about syncing two computers with smart-previews, No. Others have suggested ways to keep two computers in sync, but not using smart previews, which are for LR Mobile and working offline, not syncing two desktops.