Q-Chem

About the License

SAS Chemistry has a site license for Q-Chem for Windows, Mac, and Linux. If you have not taken advantage of this resource yet, please follow the instructions below to install the software and request a license. These instructions are for installing and licensing the software on an individual computer. Further instructions for installing Q-Chem on a shared server or accessing Q-Chem through WebMO are forthcoming.

Only valid faculty, staff, and students of Penn Arts & Sciences Chemistry are eligible for the license.

For Linux and Mac:

  1. Grab the installer
    1. Linux: wget -N https://downloads.q-chem.com/qcinstall.sh
    2. Mac: curl https://downloads.q-chem.com/qcinstall.sh > qcinstall.sh
  2. chmod +x qcinstall.sh
  3.  ./qcinstall.sh
  4. Specify installation directory – manufacturer recommends /opt/qchem/5.4.0 – make sure to specify the absolute path.
  5. Choose installation type – single-node, cluster, or single-node with NVIDIA GPU. If you’re not sure, choose single-node.
  6. Choose scratch directory – again specify absolute path.
  7. Set memory limit – generally 50%-80% of total memory capacity on the compute node.
  8. Complete registration by entering your email address and order number 8256
  9. Select licensing model – node-locked licensing will request an individual license file for the machine being set up.
  10. Your license file should arrive shortly (~25 minutes) via email.

For Windows:

  1. Grab the installer
    1. https://downloads.q-chem.com/windows/qchem-5.4.2-installer.exe
    2. or the BrianQC installer (if using NVIDIA GPU) – https://downloads.q-chem.com/windows/qchem-5.4.2-brianqc-installer.exe
  2. Launch the installer and follow the prompts to install to default directory C:\Q-Chem\5.4.2
  3. In the Start Menu under Q-Chem 5.4.2 click “Register Q-Chem” and follow the prompts
  4. Provide your email address and order number 8256
  5. Your license file should arrive shortly (~25 minutes) via email. Save it to C:\Q-Chem\5.4.2\qcaux\license\qchem.license.dat
  6. After license is received, launch Q-Chem Shell and run the following sample calculation:
    qchem dft_b3lyp_h2o.in

Further details and other use cases are discussed here.