Work-Arounds for Known Issues
This page contains work-arounds for some known issues in different Q-Chem versions. If you would like something added to this page, please reach out to support@q-chem.com.
All Q-Chem Versions
- Issues validating node-locked licenses on OSX/Mac: A recent update to Mac systems has turned on a setting that virtually changes the unique identifier for your machine (MAC address) by default whenever connecting to a new WiFi network. To stop the MAC address from randomly changing like this, you will need to turn off this setting for your WiFi networks:
- Before requesting the license, go to System Preferences->Network-WiFI and check ‘Details’. Then make sure ‘Private WiFi address’ is set to ‘Off’ (not ‘Fixed’).
- Install the license – Q-Chem now should work on this network or when you are off-line. If you already had a license issued before doing this, the license may need to be reissued (contact license@q-chem.com for a new license).
- To make Q-Chem work while you are connected to other WiFi networks, you should manually set ‘Private WiFi address’ to ‘off’ for each network after you connect to it.
- If you do want to use Private WiFi address on some networks, then the solution is to run Q-Chem when you are off-line.
- CentOS 7: CentOS 7 support ended in 2024, so it does not support Q-Chem 6.4; However, due to the number of Q-Chem customers still using CentOS 7 operating systems, we have created a Q-Chem 6.4 package specifically for CentOS 7 users. You can download the offline installer for the CentOS 7-supported version of Q-Chem 6.4 here.
Q-Chem 6.2
- FCHK files generated for IQmol are missing MO coefficients in some cases.
- Work-Around: Add "SPADE = 0" in the $rem variable section.