HPC/Applications/quantum-espresso: Difference between revisions
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* Wave function files from parallel runs are stored by MPI process number and are named sequentially <code>''prefix''.wfc''n''</code>. Subsequent calculations must use the same number of MPI processes, and each process must have access to its own ''n''. That means using a node-local directory is overly difficult. | * Wave function files from parallel runs are stored by MPI process number and are named sequentially <code>''prefix''.wfc''n''</code>. Subsequent calculations must use the same number of MPI processes, and each process must have access to its own ''n''. That means using a node-local directory is overly difficult. | ||
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With <code>''prefix''</code> being a user-specified name. | With <code>''prefix''</code> being a user-specified name. | ||
http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node9.html | http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node9.html | ||
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Revision as of 22:09, January 18, 2013
Introduction
Quantum ESPRESSO is a suite of several programs working on the same data files. This brings with it some challenges for data management, and there are some problems.
- A sample job file is at the customary location once the quantum-espresso module is loaded.
$QUANTUM_ESPRESSO_HOME/sample.job
Limitations
- QE stores rather large wave function files in the directory specified by
outdiror theESPRESSO_TMPDIRenvironment variable. This may unduly tax the file server. - In a subdirectory
prefix.save/the main QE program pw.x stores important metadata needed for subsequent calculations such as a DOS calculation. This means the…TMPpart in the nameESPRESSO_TMPDIRis misleading. - Wave function files from parallel runs are stored by MPI process number and are named sequentially
prefix.wfcn. Subsequent calculations must use the same number of MPI processes, and each process must have access to its own n. That means using a node-local directory is overly difficult.