What are the CHARMM and GCC versions you are using? The OS version alone is not enough information. In many case, the default compilers on Linux systems can be fairly old, compared to the latest GCC release.
The CHARMM version could be an issue; I just built c45b1 on Ubuntu 18.04 using the default GCC 7.5 suite, and the Ubuntu cmake utility.
Last edited by rmv; 10/24/20 05:06 PM.